All structural members and brackets are constructed of carbon steel. The 16" guide wheels for DMF RW-1630 railgear are machined from hardened steel castings and are fitted to high strength alloy steel axles with heavy-duty tapered roller bearings.
Both DMF front and rear guidewheel units bolt to the truck frame using only hand tools found in any shop. They are designed to minimize the amount of space required and in many cases fit within the existing boundaries of the vehicle. The front units, however, sometimes require a bolt-on frame extension to complete the installation. Rear RW-1630 railgear mounts below the top of frame and directly behind the chassis spring hangers.
The optional RW-1630 rail brakes are of the air actuated external Cobra shoe type. The rail brakes use a truck style air chamber to supply the clamping force. Supply pressure comes from the vehicle's air system. A pressure protection valve separates the railgear and the truck's air systems, preventing a failure in the rail brake system from adversely affecting truck braking. The rail brakes are applied simultaneously with the truck brakes when the operator presses the brake pedal. There is also a dashboard-mounted switch that permits the operator to enable or disable the rail braking system.
The truck is pulled onto a crossing and the wheels aligned to the tracks with attention being paid to the front. The operator then activates the hydraulic power unit pulling the lever of the hydraulic valve to raise the railgear off of the pin-off device. The safety pins are removed and the lever pushed forward lowering the rail wheels to the track. The front gear will lift the front of the truck and go over center. The rear is operated similarly. The gear is raised to lift the weight from the pin-offs, and the pins are removed. The gear is then lowered via the two handled valve at the rear of the truck. Each spool may be operated independently to articulate the rear gear and engage the rail even if the rear wheels are not perfectly aligned. Once the rear gear is fully deployed, the pin offs are re-inserted to lock the gear in place.
Steering Wheel Lock:
The steering stop is provided with the optional railwheel brake assembly. If the unit is not equipped with optional brakes, a steering wheel lock is provided, requiring no modifications to the column.