Tightening Hardware to Reduce Door Noise

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)

 

 

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.

 

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