The huge HO scale indoor model railroad is operated by AMRE, the Alamo Model Railroad Engineers. It is located in the museum's main display building. The layout is enormous by anyone standards. It spans the entire 100 feet length of the building, with multiple layers of tracks, yards, switching areas, turntables and towns among its many features. These will soon include an ore dock complete with a scale sized freighter. HO, which stands for "Half O, which was made popular by Lionel beginning in 1901. HO was introduced just after World War One and became increasingly popular during the Great Depression. HO is the most popular type of modern model railroading by far. Its practitioners take it very seriously. The scale of the models allows for a fantastic amount of detail. HO scale is 1:87. Every inch on HO is the equivalent of 87 inches, or 7 feet 3 inches, on what model railroaders refer to as 1:1 railroading, the kind where the rails are 4 feet 8.5 inches apart. HO rails are 16.5 mm (0.649 inches) apart. HO is the size that most people have in their own homes, maybe on table tops, or an entire room or even the garage. What we have at the Texas Transportation Museum is HO scale model railroading on a vastly higher level of complexity, one that needs many people with all the different skills needed to run such a vast operation, from electronics experts to scenery builders.

The Alamo Model Railroad Engineers run the layout almost every day the museum is open. Museum visitors love to find all the little details that bring any layout to life, especially one as large as this example at the museum. They run trains of all different types and sizes, and from multiple eras, so there is something for everyone. The group has its meetings and work sessions on Saturday evenings after the close of business. If you are interested in helping to run the layout, you would be most welcome to visit with them at this time. AMRE also runs a huge train show on the first weekend of October every year, with model train vendors from across the state of Texas and beyond setting up shop at the Live Oak Civic Center for the benefit of railroad enthusiasts of every kind. There is always an amazing amount of books, DVDs, posters and railroad memorabilia for sale as well as model trains of every size, scale and description. Click the link on the right hand side of this page for more information about San Antonio's best train show.