What to Expect from Same Day Garage Door Service

An ideal spring acts in accordance with Hooke's law, which states that the force with which the spring pushes back is linearly proportional to the distance from its equilibrium length:

$\displaystyle F=-kx$,

where

$\displaystyle x$ is the displacement vector – the distance from its equilibrium length.

$\displaystyle F$ is the resulting force vector – the magnitude and direction of the restoring force the spring exerts

$\displaystyle k$ is the rate, spring constant or force constant of the spring, a constant that depends on the spring's material and construction. The negative sign indicates that the force the spring exerts is in the opposite direction from its displacement

Most real springs approximately follow Hooke's law if not stretched or compressed beyond their elastic limit.

Coil springs and other common springs typically obey Hooke's law. There are useful springs that don't: springs based on beam bending can for example produce forces that vary nonlinearly with displacement.

If made with constant pitch (wire thickness), conical springs have a variable rate. However, a conical spring can be made to have a constant rate by creating the spring with a variable pitch. A larger pitch in the larger-diameter coils and a smaller pitch in the smaller-diameter coils forces the spring to collapse or extend all the coils at the same rate when deformed.

Since force is equal to mass, m, times acceleration, a, the force equation for a spring obeying Hooke's law looks like:

$\displaystyle F=ma\quad \Rightarrow \quad -kx=ma.\,$

The mass of the spring is small in comparison to the mass of the attached mass and is ignored. Since acceleration is simply the second derivative of x with respect to time,

$\displaystyle -kx=m\frac d^2xdt^2.\,$

This is a second order linear differential equation for the displacement $\displaystyle x$ as a function of time. Rearranging:

$\displaystyle \frac d^2xdt^2+\frac kmx=0,\,$

the solution of which is the sum of a sine and cosine:

$\displaystyle x(t)=A\sin \left(t\sqrt \frac km\right)+B\cos \left(t\sqrt \frac km\right).\,$

$\displaystyle A$ and $\displaystyle B$ are arbitrary constants that may be found by considering the initial displacement and velocity of the mass. The graph of this function with $\displaystyle B=0$ (zero initial position with some positive initial velocity) is displayed in the image on the right.

In simple harmonic motion of a spring-mass system, energy will fluctuate between kinetic energy and potential energy, but the total energy of the system remains the same. A spring that obeys Hooke's law with spring constant k will have a total system energy E of:^[14]

$\displaystyle E=\left(\frac 12\right)kA^2$

Here, A is the amplitude of the wave-like motion that is produced by the oscillating behavior of the spring.

The potential energy U of such a system can be determined through the spring constant k and its displacement x:^[14]

$\displaystyle U=\left(\frac 12\right)kx^2$

The kinetic energy K of an object in simple harmonic motion can be found using the mass of the attached object m and the velocity at which the object oscillates v:^[14]

$\displaystyle K=\left(\frac 12\right)mv^2$

Since there is no energy loss in such a system, energy is always conserved and thus:^[14]

$\displaystyle E=K+U$

The angular frequency ω of an object in simple harmonic motion, given in radians per second, is found using the spring constant k and the mass of the oscillating object m^[15]:

$\displaystyle \omega =\sqrt \frac km$^[14]

The period T, the amount of time for the spring-mass system to complete one full cycle, of such harmonic motion is given by:^[16]

$\displaystyle T=\frac 2\pi \omega =2\pi \sqrt \frac mk$^[14]

The frequency f, the number of oscillations per unit time, of something in simple harmonic motion is found by taking the inverse of the period:^[14]

$\displaystyle f=\frac 1T=\frac \omega 2\pi =\frac 12\pi \sqrt \frac km$^[14]

In classical physics, a spring can be seen as a device that stores potential energy, specifically elastic potential energy, by straining the bonds between the atoms of an elastic material.

Hooke's law of elasticity states that the extension of an elastic rod (its distended length minus its relaxed length) is linearly proportional to its tension, the force used to stretch it. Similarly, the contraction (negative extension) is proportional to the compression (negative tension).

This law actually holds only approximately, and only when the deformation (extension or contraction) is small compared to the rod's overall length. For deformations beyond the elastic limit, atomic bonds get broken or rearranged, and a spring may snap, buckle, or permanently deform. Many materials have no clearly defined elastic limit, and Hooke's law can not be meaningfully applied to these materials. Moreover, for the superelastic materials, the linear relationship between force and displacement is appropriate only in the low-strain region.

Hooke's law is a mathematical consequence of the fact that the potential energy of the rod is a minimum when it has its relaxed length. Any smooth function of one variable approximates a quadratic function when examined near enough to its minimum point as can be seen by examining the Taylor series. Therefore, the force – which is the derivative of energy with respect to displacement – approximates a linear function.

The force of a fully compressed spring is:

$\displaystyle F_max=\frac Ed^4(L-nd)16(1+\nu )(D-d)^3n\$

where

E – Young's modulus

d – spring wire diameter

L – free length of spring

n – number of active windings

$\displaystyle \nu$ – Poisson ratio

D – spring outer diameter.

Zero-length spring is a term for a specially designed coil spring that would exert zero force if it had zero length. That is, in a line graph of the spring's force versus its length, the line passes through the origin. A real coil spring will not contract to zero length because at some point the coils touch each other. "Length" here is defined as the distance between the axes of the pivots at each end of the spring, regardless of any inelastic portion in-between.

Zero-length springs are made by manufacturing a coil spring with built-in tension (A twist is introduced into the wire as it is coiled during manufacture; this works because a coiled spring unwinds as it stretches), so if it could contract further, the equilibrium point of the spring, the point at which its restoring force is zero, occurs at a length of zero. In practice, the manufacture of springs is typically not accurate enough to produce springs with tension consistent enough for applications that use zero length springs, so they are made by combining a negative length spring, made with even more tension so its equilibrium point would be at a negative length, with a piece of inelastic material of the proper length so the zero force point would occur at zero length.

A zero-length spring can be attached to a mass on a hinged boom in such a way that the force on the mass is almost exactly balanced by the vertical component of the force from the spring, whatever the position of the boom. This creates a horizontal pendulum with very long oscillation period. Long-period pendulums enable seismometers to sense the slowest waves from earthquakes. The LaCoste suspension with zero-length springs is also used in gravimeters because it is very sensitive to changes in gravity. Springs for closing doors are often made to have roughly zero length, so that they exert force even when the door is almost closed, so they can hold it closed firmly.

• Shock absorber
• Slinky, helical spring toy
• Volute spring

• Sclater, Neil. (2011). "Spring and screw devices and mechanisms." Mechanisms and Mechanical Devices Sourcebook. 5th ed. New York: McGraw Hill. pp. 279–299. ISBN 9780071704427. Drawings and designs of various spring and screw mechanisms.
• Parmley, Robert. (2000). "Section 16: Springs." Illustrated Sourcebook of Mechanical Components. New York: McGraw Hill. ISBN 0070486174 Drawings, designs and discussion of various springs and spring mechanisms.
• Warden, Tim. (2021). “Bundy 2 Alto Saxophone.” This saxophone is known for having the strongest tensioned needle springs in existence.

• Paredes, Manuel (2013). "How to design springs". insa de toulouse. Retrieved 13 November 2013.
• Wright, Douglas. "Introduction to Springs". Notes on Design and Analysis of Machine Elements. Department of Mechanical & Material Engineering, University of Western Australia. Retrieved 3 February 2008.
• Silberstein, Dave (2002). "How to make springs". Bazillion. Archived from the original on 18 September 2013. Retrieved 3 February 2008.
• Springs with Dynamically Variable Stiffness (patent)
• Smart Springs and their Combinations (patent)

 

 

These 16 + 1 leads can be reduced to just 8 by using x/y multiplexing (Figure 1, center). A 16-key keypad uses a 4 × 4 array of 4 I/O lines as outputs and 4 as inputs. A circuit is completed between an output and an input when a key is pressed. Each individual keypress creates a unique signal for the host. If required, and if the processor allows, two keys can be pressed at the same time without ambiguity. Adding diodes in series with each key prevents key ghosting, allowing multiple simultaneous presses.

8 leads can detect many more keys if tri-state multiplexing (Figure 1, right) is used instead, which enables (n-1) × (n/2) keys to be detected with just n I/O lines. 8 I/O can detect 28 individual keys without ambiguity. Issues can occur with some combinations if two keys are pressed simultaneously. If diodes are used, then the number of unique keys detectable is doubled.^[16]

• Arrow keys
• Charlieplexing
• Digital door lock
• Keyboard (computing)
• Keyboard matrix circuit
• Keyboard technology
• Key rollover
• Mobile phone
• Numeric keypad
• Push-button telephone
• Rotary dial
• Silicone rubber keypad
• Telephone keypad

• Interfacing Matrix Keypad to 8051 Controller

 

41°24′53.8″N 87°24′14.3″W / 41.414944°N 87.403972°W / 41.414944; -87.403972.

• Amtrak
• Canadian National Railway
• Chicago, Fort Wayne and Eastern Railroad
• Chicago South Shore and South Bend Railroad
• CSX Transportation
• Gary Railway
• Indiana Harbor Belt Railroad
• Norfolk Southern Railway
• South Shore Line

The municipalities in Lake County, and their populations as of the 2020 Census, are:

• Lake Dalecarlia – 1,332
• Lakes of the Four Seasons – 3,936
  (7,091 including portion in Porter County)
• Shelby – 453

The 11 townships of Lake County, with their populations as of the 2020 Census, are:

Despite the decline of heavy industry, manufacturing was still the largest employment sector in Lake County in 2010 with over 45,000 workers employed, followed closely by healthcare and social assistance at 44,000 workers, public administration at 40,000 workers, retail trade at 37,000 workers, accommodation and food services at 25,000 workers, and construction at 15,000 workers.^[18]

Lake County's GDP in 2010 was measured at nearly $25 billion. Manufacturing was also the largest sector of the economy in economic terms, contributing over $5.8 billion to the county's GDP in 2010. It was followed by healthcare and social assistance at $2.6 billion, public administration at $2.5 billion, and retail trade at $1.9 billion. While Lake County's average income was approximately 24% higher than the national average in 1978, in 2010 Lake County had fallen significantly behind the United States as a whole, with average income being approximately 12.9% lower. The national average surpassed Lake County sometime around 1986.

Businesses with the largest number of employees in the county are: ^[20]

The administration of public schools in Lake County is divided among 16 corporations and governing bodies,^[21] more than any other Indiana county.^[22]

• Crown Point Community School Corporation – Center and Winfield townships
• Gary Community School Corporation – City of Gary
• Griffith Public Schools – Town of Griffith
• Hanover Community School Corporation – Hanover Township
• Lake Central School Corporation – St. John Township
• Lake Ridge Schools Corporation – unincorporated Calumet Township
• Lake Station Community Schools – City of Lake Station
• Merrillville Community School Corporation – Ross Township
• River Forest Community School Corporation – Town of New Chicago and some portions of adjacent communities
• School City of East Chicago – City of East Chicago
• School City of Hammond – City of Hammond
• School City of Hobart – City of Hobart within Hobart Township
• School City of Whiting – City of Whiting
• School Town of Highland – Town of Highland
• School Town of Munster – Town of Munster
• Tri-Creek School Corporation – Cedar Creek, Eagle Creek and West Creek townships

Elementary and secondary schools operated by the Diocese of Gary:

Other parochial and private schools:

• St. Paul's Lutheran School, Munster (PK–8)
• Trinity Lutheran School, Crown Point (PK–8)
• Trinity Lutheran School, Hobart (PK–8)

The county is served by seven different public library systems:

• Crown Point Community Library has its main location with a branch in Winfield.^[24]
• East Chicago Public Library has its main location and the Robart A. Pastrick branch.^[25]
• Gary Public Library has its main location, the Gary Public Library and Cultural Center, and the Kennedy and Woodson branches.^[26]
• Hammond Public Library^[27]
• Lake County Public Library has its main location in Merrillville as well as Cedar Lake, Dyer-Schererville, Griffith-Calumet Township, Highland, Hobart, Lake Station-New Chicago, Munster and St. John branches.^[28]
• Lowell Public Library has its main location with branches in Schneider and Shelby.^[29]
• Whiting Public Library^[30]

• Community Hospital, Munster – 454 beds^[31]
• Franciscan Health Crown Point, Crown Point – 203 beds (Level III Trauma Center)^[31][32][33]
• Franciscan Health Dyer, Dyer – 223 beds^[31][32]
• Franciscan Health Munster, Munster – 63 beds^[31][32]
• Methodist Hospitals – 536 beds^[31]
  • Northlake Campus, Gary
  • Southlake Campus, Merrillville
• NW Indiana ER and Hospital, Hammond – 6 beds^[31]
• St. Catherine Hospital, East Chicago – 216 beds^[31]
• St. Mary Medical Center, Hobart – 215 beds^[31]
• UChicago Medicine Crown Point, Crown Point – 8 beds (opening April 2024)^[34]

The Times, based in Munster, is the largest daily newspaper in Lake County and Northwest Indiana and the second largest in the state. Lake County is also served by the Post-Tribune, a daily newspaper based in Merrillville.

Lakeshore Public Television operates WYIN-TV Gary on channel 56 and is the local PBS station in the Chicago television market.

These eight broadcast radio stations serve Lake County and are part of the Chicago market:

In recent years, average temperatures in Lowell have ranged from a low of 14.4 °F (−9.8 °C) in January to a high of 83.8 °F (28.8 °C) in July, although a record low of −29 °F (−34 °C) was recorded in December 1989 and a record high of 104 °F (40 °C) was recorded in June 1988. Average monthly precipitation ranged from 1.75 inches (44 mm) in February to 4.69 inches (119 mm) in June. Temperatures at or below 0 °F (−18 °C) occur on average 11 days annually and exceed 90 °F (32 °C) degrees on 14 days.^[35] In winter, lake-effect snow increases snowfall totals compared to the areas to the west.^[36] In spring and early summer, the immediate shoreline areas sometimes experience lake-breeze that can drop temperatures by several degrees compared to areas further inland.^[37] In summer, thunderstorms are common, occurring an average 40–50 days every year,^[38] and on about 13 days, these thunderstorms produce severe winds.^[39]

The county government is a constitutional body, and is granted specific powers by the Constitution of Indiana, and by the Indiana Code.

County Council: The county council is the legislative branch of the county government and controls all the spending and revenue collection in the county. Representatives are elected from county districts. The council members serve four-year terms. They are responsible for setting salaries, the annual budget, and special spending. The council also has limited authority to impose local taxes, in the form of an income and property tax that is subject to state level approval, excise taxes, and service taxes.^[40][41]

Board of Commissioners: The executive body of the county is made of a board of commissioners. The commissioners are elected county-wide, in staggered terms, and each serves a four-year term. One of the commissioners, typically the most senior, serves as president. The commissioners are charged with executing the acts legislated by the council, collecting revenue, and managing the day-to-day functions of the county government.^[40][41]

Court: The county maintains a small claims court that can handle some civil cases. The judge on the court is elected to a term of four years and must be a member of the Indiana Bar Association. The judge is assisted by a constable who is also elected to a four-year term. In some cases, court decisions can be appealed to the state level circuit court.^[41]

County Officials: The county has several other elected offices, including sheriff, coroner, auditor, treasurer, recorder, surveyor, and circuit court clerk Each of these elected officers serves a term of four years and oversees a different part of county government. Members elected to county government positions are required to declare party affiliations and to be residents of the county.^[41]

While the state of Indiana is strongly Republican, having voted Republican in every election since 1964 (except in 2008), Lake County has long been a Democratic stronghold due to being part of the Chicago metropolitan area. It has given pluralities or majorities to Democrats in every presidential election since 1932 with the exceptions of 1956 and 1972. Like the rest of the Rust Belt, however, Lake County has recently trended Republican, with Donald Trump scoring the highest percentage of the vote since 1972 in the 2024 presidential election.

Lake is part of Indiana's 1st congressional district, which is held by Democrat Frank J. Mrvan.^[43] In the State Senate, Lake is part of the 1st, 2nd, 3rd and 6th districts, which are held by three Democrats and one Republican. In the Indiana House of Representatives, Lake is part of the 1st, 2nd, 3rd, 11th, 12th, 14th, 15th and 19th districts, which are held by four Democrats and four Republicans.

United States presidential election results for Lake County, Indiana^[44]

Year	Republican		Democratic		Third party(ies)
	No. 	%	No. 	%	No. 	%
2024	97,270	46.30%	109,086	51.92%	3,746	1.78%
2020	91,760	41.65%	124,870	56.67%	3,700	1.68%
2016	75,625	37.29%	116,935	57.66%	10,241	5.05%
2012	68,431	33.85%	130,897	64.75%	2,819	1.39%
2008	67,742	32.41%	139,301	66.64%	1,996	0.95%
2004	71,903	38.24%	114,743	61.03%	1,376	0.73%
2000	63,389	36.02%	109,078	61.98%	3,527	2.00%
1996	47,873	29.22%	100,198	61.15%	15,789	9.64%
1992	53,867	28.91%	102,778	55.17%	29,653	15.92%
1988	79,929	43.03%	105,026	56.55%	780	0.42%
1984	94,870	44.30%	117,984	55.10%	1,289	0.60%
1980	95,408	46.02%	101,145	48.78%	10,786	5.20%
1976	90,119	42.36%	120,700	56.74%	1,922	0.90%
1972	115,480	56.24%	88,510	43.10%	1,352	0.66%
1968	77,911	36.48%	99,897	46.77%	35,766	16.75%
1964	73,722	35.19%	134,978	64.42%	823	0.39%
1960	78,278	37.04%	132,554	62.72%	526	0.25%
1956	92,803	52.00%	85,000	47.63%	657	0.37%
1952	74,073	44.66%	90,721	54.70%	1,051	0.63%
1948	51,413	38.77%	77,025	58.09%	4,157	3.14%
1944	48,147	38.84%	75,066	60.56%	737	0.59%
1940	45,898	38.79%	71,985	60.83%	447	0.38%
1936	33,689	32.47%	68,551	66.07%	1,510	1.46%
1932	42,596	46.56%	46,060	50.34%	2,836	3.10%
1928	48,768	59.68%	32,321	39.55%	630	0.77%
1924	30,990	64.61%	10,918	22.76%	6,060	12.63%
1920	26,296	69.15%	7,136	18.77%	4,596	12.09%
1916	13,262	55.00%	9,946	41.25%	903	3.75%
1912	5,176	29.61%	5,136	29.38%	7,171	41.02%
1908	9,499	60.97%	5,502	35.32%	578	3.71%
1904	6,429	64.11%	2,933	29.25%	666	6.64%
1900	5,337	58.00%	3,733	40.57%	131	1.42%
1896	4,883	58.11%	3,418	40.68%	102	1.21%
1892	2,958	48.02%	3,010	48.86%	192	3.12%
1888	2,543	54.21%	2,068	44.08%	80	1.71%

In the 2008 Democratic presidential primary on May 6, 2008, Lake County was one of the last counties to report results.^[45] Lake County had reported no results at 11 p.m. ET,^[46] and at midnight ET, only 28% of Lake County's vote had been reported.^[47] A large number of absentee ballots and a record turnout delayed the tallies, and polls closed an hour later than much of the state because Lake County is in the Central Time Zone.^[46] Early returns showed Senator Barack Obama leading by a potentially lead-changing margin, leaving the race between Senator Hillary Clinton and Obama "too close to call" until final tallies were reported.

Crime

The NWI Times reported that over 800 registered sex offenders live in Lake and Porter Counties of Indiana in 2021.^[48]

• Northwest Indiana Symphony Orchestra, concerts held at Living Hope Church – Merrillville
• Theatre at the Center, located at the Center for Visual and Performing Arts – Munster

• Ameristar Casino – East Chicago
• Horseshoe Casino – Hammond
• Majestic Star Casino – Gary
• Majestic Star Casino II – Gary
• Pierogi Fest – Whiting
• Southlake Mall – Hobart
• Three Floyds Brewing – Munster

• Gary SouthShore RailCats, an American Association professional baseball team, play their games at U.S. Steel Yard in Gary.

List of parks and recreational facilities – Lake County Parks and Recreation

List of recreational facilities – Indiana Dunes National Park

Historical population

Census	Pop.	Note	%±
1840	1,468		—
1850	3,991		171.9%
1860	9,145		129.1%
1870	12,339		34.9%
1880	15,091		22.3%
1890	23,886		58.3%
1900	37,892		58.6%
1910	82,864		118.7%
1920	159,957		93.0%
1930	261,310		63.4%
1940	293,195		12.2%
1950	368,152		25.6%
1960	513,269		39.4%
1970	546,253		6.4%
1980	522,965		−4.3%
1990	475,594		−9.1%
2000	484,564		1.9%
2010	496,005		2.4%
2020	498,700		0.5%
2023 (est.)	500,598	[49]	0.4%
U.S. Decennial Census[50] 1790-1960[51] 1900-1990[52] 1990-2000[53] 2010-2019[9]

Lake County, Indiana – Racial and ethnic composition
Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.

Race / Ethnicity (NH = Non-Hispanic)	Pop 2000[54]	Pop 2010[55]	Pop 2020[56]	% 2000	% 2010	% 2020
White alone (NH)	293,457	274,162	251,106	60.56%	55.27%	50.35%
Black or African American alone (NH)	121,372	125,506	121,048	25.05%	25.30%	24.27%
Native American or Alaska Native alone (NH)	854	913	691	0.18%	0.18%	0.14%
Asian alone (NH)	3,862	5,981	7,334	0.80%	1.21%	1.47%
Pacific Islander alone (NH)	106	63	95	0.02%	0.01%	0.02%
Other race alone (NH)	450	463	1,682	0.09%	0.09%	0.34%
Mixed race or Multiracial (NH)	5,335	6,254	16,817	1.10%	1.26%	3.37%
Hispanic or Latino (any race)	59,128	82,663	99,927	12.20%	16.67%	20.04%
Total	484,564	496,005	498,700	100.00%	100.00%	100.00%

As of the 2010 United States Census, there were 496,005 people, 188,157 households, and 127,647 families residing in the county.^[57] The population density was 994.1 inhabitants per square mile (383.8/km²). There were 208,750 housing units at an average density of 418.4 per square mile (161.5/km²).^[19] The racial makeup of the county was 64.4% white, 25.9% black or African American, 1.2% Asian, 0.3% American Indian, 5.8% from other races, and 2.4% from two or more races. Those of Hispanic or Latino origin made up 16.7% of the population.^[57] In terms of ancestry, 16.1% were German, 11.1% were Irish, 9.6% were Polish, 5.4% were English, 4.8% were Italian and 3.7% were American.^[58]

Of the 188,157 households, 34.3% had children under the age of 18 living with them, 44.7% were married couples living together, 17.4% had a female householder with no husband present, 32.2% were non-families, and 27.4% of all households were made up of individuals. The average household size was 2.60 and the average family size was 3.19. The median age was 37.4 years.^[57]

The median income for a household in the county was $47,697 and the median income for a family was $58,931. Males had a median income of $50,137 versus $33,264 for females. The per capita income for the county was $23,142. About 12.2% of families and 16.1% of the population were below the poverty line, including 25.3% of those under age 18 and 8.4% of those age 65 or over.^[59]

Places by population and race^[60]

Place	Population (2010)	White	Black or African American	Asian	Other [note 1]	Hispanic or Latino (of any race)
Lake County	496,005	64.4%	25.9%	1.2%	8.5%	16.7%
Cedar Lake, town	11,560	94.9%	0.5%	0.4%	4.2%	6.5%
Crown Point, city	27,317	88.2%	6.3%	1.8%	3.7%	8.1%
Dyer, town	16,390	90.1%	2.5%	2.9%	4.5%	9.3%
East Chicago, city	29,698	35.5%	42.9%	0.1%	21.5%	50.9%
Gary, city	80,294	10.7%	84.8%	0.2%	4.3%	5.1%
Griffith, town	16,893	75.8%	16.9%	0.8%	6.5%	13.3%
Hammond, city	80,830	59.4%	22.5%	1.0%	17.1%	34.1%
Highland, town	23,727	88.6%	4.2%	1.6%	5.6%	12.8%
Hobart, city	29,059	85.3%	7.0%	1.0%	6.7%	13.9%
Lake Dalecarlia, CDP	1,355	97.3%	0.2%	0.1%	2.4%	3.4%
Lake Station, city	12,572	79.7%	3.6%	0.3%	16.4%	28.0%
Lakes of the Four Seasons, CDP[note 2]	7,033	93.4%	1.2%	1.0%	4.4%	8.5%
Lowell, town	9,276	95.9%	0.5%	0.3%	3.3%	6.9%
Merrillville, town	35,246	46.4%	44.5%	1.2%	7.9%	12.9%
Munster, town	23,603	85.6%	3.5%	5.8%	5.1%	10.2%
New Chicago, town	2,035	81.0%	2.2%	0.7%	16.1%	27.4%
St. John, town	14,850	93.5%	1.3%	1.3%	3.9%	8.2%
Schererville, town	29,243	86.8%	5.4%	2.8%	5.0%	10.6%
Schneider, town	277	97.1%	0.0%	1.1%	1.8%	2.5%
Shelby, CDP	539	95.5%	1.7%	0.2%	2.6%	0.9%
Whiting, city	4,997	76.3%	3.5%	0.7%	19.5%	40.7%
Winfield, town	4,383	88.5%	3.7%	3.5%	4.3%	8.9%

Places by population and standard of living^[61][62]

Place	Population (2010)	Per capita income	Median household income	Median home value
Lake County	496,005	$23,792	$49,315	$137,400
Cedar Lake, town	11,560	$25,477	$59,090	$151,400
Crown Point, city	27,317	$31,454	$64,876	$174,900
Dyer, town	16,390	$35,020	$78,881	$197,500
East Chicago, city	29,698	$13,457	$27,171	$86,800
Gary, city	80,294	$15,764	$26,956	$66,900
Griffith, town	16,893	$26,548	$53,225	$141,600
Hammond, city	80,830	$18,148	$38,677	$94,800
Highland, town	23,727	$30,036	$61,930	$155,200
Hobart, city	29,059	$24,740	$54,468	$134,400
Lake Dalecarlia, CDP	1,355	$25,035	$52,321	$165,400
Lake Station, city	12,572	$16,953	$36,955	$82,400
Lakes of the Four Seasons, CDP[note 2]	7,033	$32,908	$84,242	$182,600
Lowell, town	9,276	$23,619	$60,549	$146,500
Merrillville, town	35,246	$23,605	$53,470	$132,600
Munster, town	23,603	$34,735	$70,708	$197,600
New Chicago, town	2,035	$18,083	$38,672	$97,700
St. John, town	14,850	$36,490	$97,868	$254,600
Schererville, town	29,243	$33,984	$68,004	$204,300
Schneider, town	277	$18,774	$50,972	$89,500
Shelby, CDP	539	$29,700	$61,667	$89,700
Whiting, city	4,997	$21,427	$44,368	$111,500
Winfield, town	4,383	$23,792	$49,315	$137,400

• Lake County Indiana Sheriff's Department
• List of public art in Lake County, Indiana
• National Register of Historic Places listings in Lake County, Indiana

• Forstall, Richard L. (1995). U. S. Population of States and Counties - 1790 Through 1990. National Technical Information Services (NTIS). ISBN 0-934213-48-8.
• Schoon, Kenneth J. (2003). Calumet Beginnings: Ancient Shorelines and Settlements at the South End of Lake Michigan. Indiana University Press. ISBN 0-253-34218-X.

• Lake County official website
• Lake County Parks
• South Shore Convention & Visitors Authority

 

The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure and supporting utilities in industrial, business, and residential installations.^[1][2] Terms such as "predictive" or "planned" maintenance describe various cost-effective practices aimed at keeping equipment operational; these activities occur either before^[3] or after a potential failure.

Maintenance functions can be defined as maintenance, repair and overhaul (MRO), and MRO is also used for maintenance, repair and operations.^[4] Over time, the terminology of maintenance and MRO has begun to become standardized. The United States Department of Defense uses the following definitions:^[5]

• Any activity—such as tests, measurements, replacements, adjustments, and repairs—intended to retain or restore a functional unit in or to a specified state in which the unit can perform its required functions.^[5]
• All action taken to retain material in a serviceable condition or to restore it to serviceability. It includes inspections, testing, servicing, classification as to serviceability, repair, rebuilding, and reclamation.^[5]
• All supply and repair action taken to keep a force in condition to carry out its mission.^[5]
• The routine recurring work required to keep a facility (plant, building, structure, ground facility, utility system, or other real property) in such condition that it may be continuously used, at its original or designed capacity and efficiency for its intended purpose.^[5]

Maintenance is strictly connected to the utilization stage of the product or technical system, in which the concept of maintainability must be included. In this scenario, maintainability is considered as the ability of an item, under stated conditions of use, to be retained in or restored to a state in which it can perform its required functions, using prescribed procedures and resources.^[6]

In some domains like aircraft maintenance, terms maintenance, repair and overhaul^[7] also include inspection, rebuilding, alteration and the supply of spare parts, accessories, raw materials, adhesives, sealants, coatings and consumables for aircraft maintenance at the utilization stage. In international civil aviation maintenance means:

• The performance of tasks required to ensure the continuing airworthiness of an aircraft, including any one or combination of overhaul, inspection, replacement, defect rectification, and the embodiment of a modification or a repair.^[8]

This definition covers all activities for which aviation regulations require issuance of a maintenance release document (aircraft certificate of return to service – CRS).

The marine and air transportation,^[9] offshore structures,^[10] industrial plant and facility management industries depend on maintenance, repair and overhaul (MRO) including scheduled or preventive paint maintenance programmes to maintain and restore coatings applied to steel in environments subject to attack from erosion, corrosion and environmental pollution.^[10]

The basic types of maintenance falling under MRO include:

• Preventive maintenance, where equipment is checked and serviced in a planned manner (in a scheduled points in time or continuously)
• Corrective maintenance, where equipment is repaired or replaced after wear, malfunction or break down
• Reinforcement^[11]

Architectural conservation employs MRO to preserve, rehabilitate, restore, or reconstruct historical structures with stone, brick, glass, metal, and wood which match the original constituent materials where possible, or with suitable polymer technologies when not.^[12]

Preventive maintenance (PM) is "a routine for periodically inspecting" with the goal of "noticing small problems and fixing them before major ones develop."^[13] Ideally, "nothing breaks down."^[14]

The main goal behind PM is for the equipment to make it from one planned service to the next planned service without any failures caused by fatigue, extreme fluctuation in temperature(such as heat waves^[15]) during seasonal changes, neglect, or normal wear (preventable items), which Planned Maintenance and Condition Based Maintenance help to achieve by replacing worn components before they actually fail. Maintenance activities include partial or complete overhauls at specified periods, oil changes, lubrication, minor adjustments, and so on. In addition, workers can record equipment deterioration so they know to replace or repair worn parts before they cause system failure.

The New York Times gave an example of "machinery that is not lubricated on schedule" that functions "until a bearing burns out." Preventive maintenance contracts are generally a fixed cost, whereas improper maintenance introduces a variable cost: replacement of major equipment.^[13]

Main objective of PM are:

1. Enhance capital equipment productive life.
2. Reduce critical equipment breakdown.
3. Minimize production loss due to equipment failures.

Preventive maintenance or preventative^[16] maintenance (PM) has the following meanings:

• The care and servicing by personnel for the purpose of maintaining equipment in satisfactory operating condition by providing for systematic inspection, detection, and correction of incipient failures either before they occur or before they develop into major defects.
• The work carried out on equipment in order to avoid its breakdown or malfunction. It is a regular and routine action taken on equipment in order to prevent its breakdown.^[17]
• Maintenance, including tests, measurements, adjustments, parts replacement, and cleaning, performed specifically to prevent faults from occurring.

Other terms and abbreviations related to PM are:

• scheduled maintenance^[18]
• planned maintenance,^[19] which may include scheduled downtime for equipment replacement
• planned preventive maintenance (PPM) is another name for PM^[20]
• breakdown maintenance:^[20] fixing things only when they break. This is also known as "a reactive maintenance strategy"^[21] and may involve "consequential damage."^[22]

Planned preventive maintenance (PPM), more commonly referred to as simply planned maintenance (PM) or scheduled maintenance, is any variety of scheduled maintenance to an object or item of equipment. Specifically, planned maintenance is a scheduled service visit carried out by a competent and suitable agent, to ensure that an item of equipment is operating correctly and to therefore avoid any unscheduled breakdown and downtime.^[23]

The key factor as to when and why this work is being done is timing, and involves a service, resource or facility being unavailable.^[18][19] By contrast, condition-based maintenance is not directly based on equipment age.

Planned maintenance is preplanned, and can be date-based, based on equipment running hours, or on distance travelled.

Parts that have scheduled maintenance at fixed intervals, usually due to wearout or a fixed shelf life, are sometimes known as time-change interval, or TCI items.

Predictive maintenance techniques are designed to help determine the condition of in-service equipment in order to estimate when maintenance should be performed. This approach promises cost savings over routine or time-based preventive maintenance, because tasks are performed only when warranted. Thus, it is regarded as condition-based maintenance carried out as suggested by estimations of the degradation state of an item. The main promise of predictive maintenance is to allow convenient scheduling of corrective maintenance, and to prevent unexpected equipment failures.^[3] This maintenance strategy uses sensors to monitor key parameters within a machine or system, and uses this data in conjunction with analysed historical trends to continuously evaluate the system health and predict a breakdown before it happens.^[24] This strategy allows maintenance to be performed more efficiently, since more up-to-date data is obtained about how close the product is to failure.^[25]

Predictive replacement is the replacement of an item that is still functioning properly.^[26] Usually it is a tax-benefit based ^{[citation needed]} replacement policy whereby expensive equipment or batches of individually inexpensive supply items are removed and donated on a predicted/fixed shelf life schedule. These items are given to tax-exempt institutions.^{[27][citation needed]}

Condition-based maintenance (CBM), shortly described, is maintenance when need arises. Albeit chronologically much older, It is considered one section or practice inside the broader and newer predictive maintenance field, where new AI technologies and connectivity abilities are put to action and where the acronym CBM is more often used to describe 'condition Based Monitoring' rather than the maintenance itself. CBM maintenance is performed after one or more indicators show that equipment is going to fail or that equipment performance is deteriorating.

This concept is applicable to mission-critical systems that incorporate active redundancy and fault reporting. It is also applicable to non-mission critical systems that lack redundancy and fault reporting.

Condition-based maintenance was introduced to try to maintain the correct equipment at the right time. CBM is based on using real-time data to prioritize and optimize maintenance resources. Observing the state of the system is known as condition monitoring. Such a system will determine the equipment's health, and act only when maintenance is actually necessary. Developments in recent years have allowed extensive instrumentation of equipment, and together with better tools for analyzing condition data, the maintenance personnel of today is more than ever able to decide what is the right time to perform maintenance on some piece of equipment. Ideally, condition-based maintenance will allow the maintenance personnel to do only the right things, minimizing spare parts cost, system downtime and time spent on maintenance.

Despite its usefulness of equipment, there are several challenges to the use of CBM. First and most important of all, the initial cost of CBM can be high. It requires improved instrumentation of the equipment. Often the cost of sufficient instruments can be quite large, especially on equipment that is already installed. Wireless systems have reduced the initial cost. Therefore, it is important for the installer to decide the importance of the investment before adding CBM to all equipment. A result of this cost is that the first generation of CBM in the oil and gas industry has only focused on vibration in heavy rotating equipment.

Secondly, introducing CBM will invoke a major change in how maintenance is performed, and potentially to the whole maintenance organization in a company. Organizational changes are in general difficult.

Also, the technical side of it is not always as simple. Even if some types of equipment can easily be observed by measuring simple values such as vibration (displacement, velocity or acceleration), temperature or pressure, it is not trivial to turn this measured data into actionable knowledge about the health of the equipment.

As systems get more costly, and instrumentation and information systems tend to become cheaper and more reliable, CBM becomes an important tool for running a plant or factory in an optimal manner. Better operations will lead to lower production cost and lower use of resources. And lower use of resources may be one of the most important differentiators in a future where environmental issues become more important by the day.

Another scenario where value can be created is by monitoring the health of a car motor. Rather than changing parts at predefined intervals, the car itself can tell you when something needs to be changed based on cheap and simple instrumentation.

It is Department of Defense policy that condition-based maintenance (CBM) be "implemented to improve maintenance agility and responsiveness, increase operational availability, and reduce life cycle total ownership costs".^[28]

CBM has some advantages over planned maintenance:

• Improved system reliability
• Decreased maintenance costs
• Decreased number of maintenance operations causes a reduction of human error influences

Its disadvantages are:

• High installation costs, for minor equipment items often more than the value of the equipment
• Unpredictable maintenance periods cause costs to be divided unequally.
• Increased number of parts (the CBM installation itself) that need maintenance and checking.

Today, due to its costs, CBM is not used for less important parts of machinery despite obvious advantages. However it can be found everywhere where increased safety is required, and in future will be applied even more widely.^[29][30]

Corrective maintenance is a type of maintenance used for equipment after equipment break down or malfunction is often most expensive – not only can worn equipment damage other parts and cause multiple damage, but consequential repair and replacement costs and loss of revenues due to down time during overhaul can be significant. Rebuilding and resurfacing of equipment and infrastructure damaged by erosion and corrosion as part of corrective or preventive maintenance programmes involves conventional processes such as welding and metal flame spraying, as well as engineered solutions with thermoset polymeric materials.^[31]

•  This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22. (in support of MIL-STD-188).

• Maintenance Planning, Coordination & Scheduling, by Don Nyman & Joel Levitt Maintenance ISBN 978-0831134181
• The Care of Things. Ethics and Politics of maintenance, by Jérôme Denis & David Pontille, Polity Press ISBN 978-1509562381

• Wu, S.; Zuo, M.J. (2010). "Linear and nonlinear preventive maintenance" (PDF). IEEE Transactions on Reliability. 59 (1): 242–249. doi:10.1109/TR.2010.2041972. S2CID 34832834. Archived (PDF) from the original on 2016-08-18.

 

US: /ɡəˈrɑːʒ, -rɑːdʒ/ gə-RAHZH, -⁠RAHJ) is a walled, roofed structure with a door for storing a vehicle or vehicles that may be part of or attached to a home ("attached garage"), or a separate outbuilding or shed ("detached garage"). Residential garages typically have space for one or two cars, although three-car garages are used. When a garage is attached to a house, the garage typically has an entry door into the house, called the person door or man door, in contrast with the wider and taller door for vehicles, called the garage door, which can be opened to permit the entry and exit of a vehicle and then closed to secure the vehicle. A garage protects a vehicle from precipitation, and, if it is equipped with a locking garage door, it also protects the vehicle(s) from theft and vandalism. Most garages also serve multifunction duty as workshops for a variety of projects, including painting, woodworking, and assembly. Garages also may be used for other purposes as well, such as storage or entertainment.

Some garages have an electrical mechanism to automatically open or close the garage door when the homeowner presses a button on a small remote control, along with a detector that stops the movement of the garage if something is in the way of closing. Some garages have enough space, even with cars inside, for the storage of items such as bicycles or a lawnmower; in some cases, there may even be enough space for a workshop or a man cave. Garages that are attached to a house may be built with the same external materials and roofing as the house. Garages that are not connected to the home may use a different style of construction from the house. Often in the Southern and rural United States garages not attached to the home and made from a timber frame with sheet metal coverings are known as "pole barns", but usually serve the same purpose as what is called a garage elsewhere. In some places, the term is used synonymously with "carport", though that term normally describes a structure that, while roofed, is not completely enclosed. A carport protects the vehicle to some degree from inclement weather, but it does not protect the vehicle from theft or vandalism.

The word garage, introduced to English in 1902, originates from the French word garer, meaning shelter.^[1] By 1908 the architect Charles Harrison Townsend was commenting in The Builder magazine that "for the home of the car, we very largely use the French word 'garage', alternatively with what I think the more desirable English equivalent of 'motor house'".^[2] Today the word is polysemic because it can refer to a collection of vehicles as well as the building that contains them.

In northern climates, temperatures inside an uninsulated attached residential garage can decrease to freezing levels during the winter. Temperatures inside an uninsulated attached garage in temperate climates can reach uncomfortable levels during summer months. Extreme temperatures can be a source of energy waste and discomfort in adjoining living areas, due to heat transfer between the garage and those areas. Homes with an attached garage often experience this "interface" problem. Insulating the outside of the building against the elements without extending the insulation to the wall separating the garage from the house, and/or the other garage walls and roof, can be a costly mistake.^[3]

Australian homes typically have a two, one and a half or double car garage, with some newer houses having a triple garage, with one double door and one single door. Prior to the 1970s most of them were detached from the house, usually set further back with the driveway leading up past the side of the house, common with old fibreboard houses, but not uncommon with earlier brick houses. The most common doors on these garages were either two wooden barn style doors with a standard sized access door on the side of the garage or the B&D Rolla Door, which is described below.

The most common garage door to date in Australia is the B&D Rolla Door, having been around since 1956 and still in heavy use today. They are a corrugated flexible but strong sheet steel door, sliding up tracks and rolling around a drum mounted above the door opening on the inside of the garage. These come in manual and remote controlled electric (known as the Control-a-Door), with conversion kits available. Locking is provided by a key lock in the centre of the door moving two square sliding lock bars in and out of holes in the door tracks, locking and unlocking it, or by the solenoid lock in the automatic motor.

Newer homes feature more American styled tilting panel lift doors which slide up onto a track on the ceiling via a motor and chain drive. Since the late 1970s most if not all garages are attached, and throughout the 80's it became more common to have an access door into the home from the garage where design permitted, whereas it is commonplace now. Most older unit (apartment) blocks in Australia have garages on the ground floor accessible through a common hallway and access doors, all leading into a common driveway. Newer ones now have underground parking.

Australia has strict guidelines in place when building a home and the garage size must conform to the Australian Standards. The minimum size for a single garage is 3.0 m × 5.4 m (9.8 ft × 17.7 ft) and a double is 5.4 m × 5.4 m (17.7 ft × 17.7 ft). However, to comfortably fit two cars in a double garage it is typical to have a size of 6.0 m × 6.0 m (19.7 ft × 19.7 ft).^[4]

British homes featuring a garage typically have a single or double garage either built into the main building, detached within the grounds (often in the back garden), or in a communal area.

Traditionally, garage doors were wooden, opening either as two leaves or sliding horizontally. Newer garages are fitted with metal up-and-over doors. Increasingly, in new homes, such doors are electrically operated.

Typically, a small British single garage is 8 by 16 feet (2.4 m × 4.9 m), a medium single garage is 9 by 18 feet (2.7 m × 5.5 m), and a large single garage is 10 by 20 feet (3.0 m × 6.1 m). Family sedans have become bigger than they were in the past, so the larger size has become a preferred option. A typical large family car like the Ford Mondeo is about 15 by 6 feet (4.6 m × 1.8 m), meaning that even with the larger size garage, it is necessary to park to one side to be able to open the driver's door wide enough to enter or exit the vehicle.

In the early days of the motor car, a garage played an important role in protecting the vehicle from the weather (particularly so as to reduce rust). It was also the case that early motor cars started more easily when they were warm,^[5] so that keeping them in a garage rather than outside made it easier to get the engine going in the morning. Modern motor cars, however, are very well protected against rust, and modern engines start with no difficulty even in very cold conditions.

The common term for these structures in the first decades of the 20th century was motor house. Many garages from before 1914 were pre-fabricated, typically by companies such as Norwich manufacturer Boulton & Paul Ltd. The style was usually in keeping with that of the house and its locale, however, they were mainly of timber construction and few have survived.^[6]

E. Keynes Purchase, "honorary architect" to what was to become the Royal Automobile Club, did a lot of work on them and recommended in The Car Illustrated in 1902, that they be of brick construction with cement floor, an inspection pit, good electric lighting and a pulley system for removing parts of the car (in the early days of motoring many car owners were mechanical and engineering enthusiasts).^[7]

The architecture of garages was ignored in the architectural journals despite famous architects such as Edwin Lutyens, Richard Barry Parker and Edgar Wood all designing garages for their wealthy clients. Charles Harrison Townsend was one of the few architects who put pen to paper (in The Builder in 1908) on the subject and recommended that the walls be glazed brick for ease of washing, air gratings to be low (petrol fumes are heavier than air), and drains half open to avoid build-up of gases.^[8]

By 1910 corrugated iron and asbestos were being used instead of wood and garages became less imposing. From 1912 speculatively built houses in London were being built with motor houses.^[9]

Many garage doors open upward using an electric chain drive, which can often be automatically controlled from inside the resident's vehicle with a small radio transmitter.^[10] Garages are connected to the nearest road with a driveway. Interior space for one or two cars is normal, and garages built after 1950 usually have a door that connects the garage directly to the interior of the house (an "attached garage"). Earlier garages were often detached and located in the back yard of the house, accessed either via a long driveway or from an alley.

In the past, garages were often separate buildings from the house ("detached garage"). On occasion, a garage would be built with an apartment above it, which could be rented out. As automobiles became more popular, the concept of attaching the garage directly to the home grew into a common practice. While a person with a separate garage must walk outdoors in every type of weather, a person with an attached garage has a much shorter walk inside a building.

Around the start of the 21st century, companies began offering "portable garages" in the United States. Typically, these garages are made of metal, wood or vinyl and do not connect to the house or other structure, much like the garage built before 1950. This portable garages usually have a strongly reinforced floor to hold a heavy vehicle. Garages are also produced as composite fabric garages with metal frames that are lightweight and portable garage compared to traditional brick-and-mortar or metal garage structures.^[11]

Over the past fifteen years, the portable garage has further evolved into a modular garage or a partially prefabricated structure. The modular garage comes from a factory that assembles the garage in two sections and combines the two sections on location. Partially prefabricated garages are often larger and might even include an attic space or a second floor. Sections of the garage are preassembled and then setup on site over a few days time.^[12] The Amish have become popular builders of portable, modular and partially prefabricated garages.

Garage sizes in the United States vary depending on the number of vehicles they are designed to accommodate. While dimensions can differ based on specific needs and local building codes, typical sizes are as follows:

• One-car garage: Usually 12 to 18 feet wide and 20 to 30 feet deep, with a total area of 240 to 540 square feet.
• Two-car garage: Commonly 20 to 24 feet wide, maintaining the same depth, and covering 360 to 660 square feet.
• Three-car garage: Typically 30 to 36 feet wide, providing 600 to 1,260 square feet of space.
• Four-car garage: The largest standard size, ranging from 40 to 48 feet wide, with a total area of 800 to 1,600 square feet.

These dimensions offer enough space not only for vehicles but also for storage and accessibility. Garage sizes may vary depending on design preferences, vehicle types, and additional space requirements.^[13]

Often in more rural settings, detached post-frame garages are used to store farm and workshop equipment and can either be cold storage^[14] or insulated for warm storage.^[15][16]

The first planned private garages appeared long before 1900. Early examples of planned public garages appeared at the same time. The first recorded public parking garage in the US (Electric Vehicle Company Garage,^[17] Chicago) was built in 1898, in the UK (Christal Palace Garage,^[18] London) in 1900 and in Germany (Großgarage der Automüller G.m.b.H.,^[19] Berlin-Wilmersdorf) in 1901.

Possibly the oldest existing garage in the United Kingdom is in Southport Lancashire. It was the first motor house or garage to be depicted in an English motoring journal and was in The Autocar of 7 October 1899. It was owned by Dr W.W. Barratt, a local doctor and motoring pioneer and specially designed for his house at 29 Park Crescent Hesketh Park. A two-storey building that matched the style of the house; the ground floor garage having a concrete floor, heating, electric lighting, an engine pit and was fully equipped. The motor house is now in residential use.^[20]

One of the oldest surviving private garages in Germany today is the 1903 finished Automobil-Remise (automobile carriage house) of Villa Esche by Henry van de Velde in Chemnitz. Carl Benz, the inventor of the automobile, had a tower built for himself in 1910, on the first floor a room for studying, on the ground floor car parking space. It still exists in Ladenburg, Germany.

• 
   
• 
  1919
• 
  1938
• 
  Garage of Hôtel Brion (1904)
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• 
  Garages in Nizhny Novgorod
• 
  Old garages in Mannheim

Garages in the United States and Canada used to store streetcars and buses are often referred to as carhouses or car barns. These storage facilities are either metal or brick structures used to store streetcars or buses away from the elements. In Britain they are referred to as bus depots or depots.

• Carport
• Carriage house
• Parking
• Proof-of-parking

• Minnis, John (2010). "Practical yet Artistic: The Motor House 1895–1914". In Brandwood, Geoffrey K. (ed.). Living Leisure and Law: Eight Building Types in England 1800–1914. Reading: Spire Books in association with the Victorian Society. ISBN 9781904965-27-5. OCLC 835667261.

• The dictionary definition of garage at Wiktionary
• Media related to Garages at Wikimedia Commons