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.

Best of the Web (“Hall of Fame”)



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

Airfix Model Railways

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

Gateway NMRA

This great reference site for model railroaders, from the Gateway (St. Louis) division of the NMRA (National Model … [read review or visit site]

Postwar Lionel Trains Library

Postwar Lionel Trains Library

Bernie Schulz’s Lionel Trains Library focuses exclusively on postwar Lionel trains and accessories. The site cont… [read review or visit site]

Eric's Trains

Eric's Trains

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

Tech Model Railroad Club of MIT

Tech Model Railroad Club of MIT

MIT's model railroad club, as one might expect, has one of the best websites for learning about how people play wit… [read review or visit site]

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Recent News: HO Scale Model Trains

Source: Google News

Shell Point model train opens for season Oct. 5
The News-Press, October 4th

Volunteer residents operate the 40-foot by 40-foot H-O scale railroad in the shape of Florida, with free tours Monday, Wednesday and Friday from October through April. Key Florida landmarks dot their approximate map site, including Walt Disney World...Read more

All aboard: Colorado Model Railroad Museum 'a place of joy'
BizWest Media, October 2nd

The HO-scale railroad – dubbed “the finest model railroad I've ever seen” by Jim Hediger, the 30-year senior editor of Model Railroader magazine – also probably is the second-longest model railroad in the world. Hamburg, Germany, spent some $50 million ...Read more

Model-train show scheduled for Nov. 1 in Mont Alto
Herald-Mail Media, September 29th

The club is planning for more than 100 vendor tables with N-, HO- and O-scale model trains, as well as parts. A model-train display will be featured. The show also will include door prizes and food. Admission is $3 per person or $5 for a family with...Read more

HO-scale railroad ready for viewing
SaukValley.com, September 25th

Its HO-scale model railroad will be active from 10 a.m. to 4 p.m. Oct. 10 and 11 at 1055 W. Beach St. The clubhouse is the large tan building behind the Canadian National Yard office on Fever River Place. Admission is $4 for adults, $1 for children, or...Read more

Just the ticket: Northwest Iowa Model Railroad Club still chugging along after ...
Worthington Daily Globe, September 24th

A “N” scale train layout by Larry Pedley will feature some of the smaller trains in the model train world. Davids noted the “N” scale trains are roughly half the size of the “H-Oscale trains used by the club. Spectators can vote for their favorites...Read more

Model Train Show Returns October 3-4 to Railroad Museum
Galveston.com & Company (press release) (blog), September 21st

Not only will there be model train and Lego layouts, but vendors will be selling model trains – locomotives, train cars, track, scenery and accessories – in all scales including the most popular O, HO, N, G and Z scales. Judging events will include...Read more

Roundhouse Model Train Association in Redlands seeks spot to meet
Redlands Daily Facts, September 18th

The nonprofit club comprises railroad enthusiasts collecting historically accurate HO scale model trains sometimes costing upwards of $400 per completed train. The term HO refers to the most popular scale of model railway in the world, according to...Read more

Train enthusiasts on track for annual model train show
Temple Daily Telegram, September 15th

Noel Cowling, 78, leans over a long wooden table and adjusts a model railroad engine on its tracks in one of several layouts in the old Moody Depot on Avenue B. The HO locomotive meanders through a maze of miniature working lights, switching stations ...Read more