A Module Working Group including NMRA and O Scale Central people started reviewing and developing module Standards and Recommended Practices in February of 2025.
The goal of this group is to make it possible for O Scalers to bring modules to an event and connect them with others to create a larger O Scale railroad that all participants can enjoy, as well as being observed by non-participants.
Modules are an important way to start O Scale 2 Rail layouts regardless of the size of the space available. Modules are popular in all scales and are frequently displayed during local train shows and NMRA events.
There are also other construction details for portable or movable model railroad layouts listed here.
A module is a portable table-like structure which is part of a group of similar tables which when assembled together form a large and fully operable model railroad. A module is designed to fit anywhere in the layout, and in any orientation of endplates.
A section (as opposed to “module”), is a portable table-like structure or section of bench work which is part of a group of similar tables which when assembled together form a large and fully operable model railroad. Each section fits in a specific place and orientation in the overall layout.
Free-mo.org, has promulgated an HO standard. The objective of the Free-Mo Standard is paraphrased as follows: to provide a platform for prototype modeling in a flexible, modular environment with modules that emphasize realistic, plausible scenery, track work, and operation. Free-Mo goes beyond the traditional closed-loop set-up by creating a truly universal “free-form” modular design that is operations oriented and heavily influenced by prototype railroading. This concept primarily serves model railroaders who like to operate trains in a prototypical fashion.