Dubbed the O4 for being the 4th Optical rail measurement vehicle in the company's history, this F550 Chassis was heavily modified from factory to meet clearance requirements for a number of transit railways. I designed and participated in construction of the whole build. It uses hydraulically-deployed steel rail wheels to travel down track while measuring full-rail cross-sectional profiles and track geometry. It also tows additional measurement hardware when required.

Critical items through the design process were ensuring stakeholder participation for operator user interface/ergonomics, as well as understanding future client needs such as clearance envelopes, grade climbing abilities, and space for optional equipment packages. 

The O4 has successfully completed optical and geometry data collection at several heavy-haul and transit clients since its commissioning in late 2021! Nothing like driving on rail through an 80-foot radius curve, backwards, through the Boston Central Subway at 2AM...

After extensive research, our team decided upon DMF's 1019B hyrail gear due to its ability to travel through incredibly tight curvature and reputation for reliability. The hydraulically actuated train wheels are lowered at grade crossings to ride along track, with the rear rubber tires maintaining top of rail contact for propulsion.

Off the rear of the truck, these cameras are deployed manually with a spring-assist that's typically installed on trailer gates! The optical cameras measure cross-sectional rail profile at 6-inch or larger spacing to aid in rail maintenance planning (e.g. rail replacement, grinding, milling).

Off the front of the truck, this was a late add-on during the build. The geometry system measures critical information as the truck travels that can be used for FRA compliance monitoring and to aid in track maintenance planning (e.g. ballasted track tamping).