HO scale model trains are 1/87 the size of real trains and 1/2 the size of O scale model trains (HO stands for "half O"). As with O scale trains, the letter "O" in HO is a misnomer since the designation was initially conceived as a zero to identify trains that were smaller in scale than 1. But the use of the letter O rather than the numeral 0 crept into everyday speech among model-train buffs and remains the standard way to refer to HO scale today.

Though first invented in the 1930s, HO scale model trains didn’t become popular in the U.S. and Europe until the 1950s when the scale was heavily promoted by Märklin, Lionel, Athearn, and others. HO never quite gained acceptance in England, though, where larger 00 scale trains still predominate.

HO has two important benefits over trains of larger sizes. First, an HO scale layout of reasonably ambitious detail and complexity can fit on a table rather than requiring an entire room, as is the case with larger scales. Second, HO trains are less expensive to manufacture than OO, O, and other large-scale trains, which makes them more affordable to collectors and enthusiasts alike.

Most HO scale trains run on two-rail tracks using direct current (DC). Adjusting the voltage delivered to the tracks can increase or decrease the speed of the trains; reversing the polarity causes the trains to roll in reverse. Some manufacturers, notably Märklin, produce HO scale trains that operate on alternating current (AC), which is delivered to the train via a conductive third rail.

The gauge used by the majority of HO scale model trains is a standard HO gauge track that’s roughly proportional to the size of the trains running on top of it. But as with the OO scale trains in England that run on HO gauge tracks, HO scale trains are also made to run on a variety of different gauge tracks, which themselves are scaled-down versions of historical railroad track sizes.

Of these variants, the most common is called HOn3. This code denotes an HO scale train running on a track similar to the 3-foot, narrow gauge tracks used by Rocky Mountain railroad operators in the late 19th century.

One of the most enjoyable aspects of HO for collectors is the opportunity to join a local module club. Members of such clubs build modules of predetermined size; each module has a finite length of track. When members get together at model train exhibitions or in private homes, the modules are linked up and trains are run on the resulting massive layout, which often feels like more than just the sum of its parts.

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This site is a treasure trove of HO scale model railroad manufacturer catalogs and other reference information, inv… [read review or visit site]

Airfix Model Railways

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Dave McCarthy's Airfix Model Railway treasure trove is an in-depth archive of the company's plastic railway kits fr… [read review or visit site]

Gateway NMRA

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Postwar Lionel Trains Library

Postwar Lionel Trains Library

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Eric's Trains

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Eric Siegel's site displays his collection of O-gauge/O-scale trains, tracks, turntables, and other accessories. A … [read review or visit site]

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Recent News: HO Scale Model Trains

Source: Google News

Railroad club thrills area children
Alton Telegraph, July 3rd

Residents in attendance are treated to an explanation and demonstration of the 18.6 by 27.6 foot HO scale layout model train track that takes up a majority of the building. The track has roughly 1,000 feet of a multiple layers. Those in attendance are...Read more

Open House and Train Show
Omaha World-Herald, July 1st

They have been promoting their Open House & Train Show since last May and the response from train enthusiasts has been very exciting. Knowing the community is in a very rural location, Dave ... We have chosen 3 HO model railroad clubs that showcase a...Read more

Model Railroad Club does Red, White and Blue July 4
Crossville Chronicle, July 1st

Red, white and blue trains, historic cars and an army base and train will be on display along with the club's usual 4,500 square feet of operating model trains. Also open will be the Upper Cumberland Railroad Society railroad ... The club operates...Read more

Spring Creek Model Trains thrives in rural Nebraska
Lincoln Journal Star, June 27th

When a train whistle blew, Dave's mother knew where her son would be. “I would always watch the train until it left town,” Dave, 57, said. When he was 10 years old, he received his first model trains as a Christmas gift, an HO scale set produced by...Read more

Model train store on track for a 'wow factor'
Hastings Tribune, June 26th

Invited guests — including model train clubs from Corpus Christi, Texas, Denver, Colo., and Free-mo, a nationwide club with chapters across the country — will exhibit some of the latest product coming down the track today. Included in the show will...Read more

ig tiny trains: Model rail club visits valley
Conway Daily Sun, June 23rd

Approximately 100 model train enthusiasts throughout the country are staying at the resort this week for the convention, celebrating their love of model trains while also taking rides on real trains such as the Mount Washington Cog Railway and the...Read more

Marion man a finalist in Lionel train competition
McDowell News, June 20th

The Train Shop was probably the best and most extensive model railroad store anywhere between Salisbury and Murphy. The shop had all kinds of antique railroad memorabilia in addition to trains and accessories in N, HO, O and G scales. And there were ...Read more

Next model train open house to be held June 20
Log Cabin Democrat, June 13th

Kids who love Thomas trains will enjoy the fun of operating HO-scale trains. Thomas, Percy, James, Emily, and Gordon characters will be running on the tracks. Bob Huber, the CAMRC Coach at this layout, will show kids how to run the trains as a hands-on ...Read more