compartments under the trailer
Sometimes departments will design their tractor drawn aerial with extra compartments under their trailer for extra storage space, for such things as plywood, extra cribbing, etc. The first two pictures are of a compartment located towards the back undercarriage of a trailer. The third picture is a department's drawing showing the location of a compartment under the trailer. (Click to enlarge)
yes or no to compartments under the trailer?
This kind of compartment location can have an adverse effect on the incredible maneuverability of this type of apparatus. One function that can make the tractor drawn aerial so maneuverable in tight areas is the trailers ability to pass over potential obstacles. It’s for this reason that I’m against adding compartments under the trailer. It’s important to protect anything that would inhibit the turning radius of your tractor drawn aerial.
examples without compartments
Below are examples demonstrating how the trailer maneuvers over obstacles. Due to tight circumstances there are times when the trailer must pass over a curb or traffic circle/calming circle. (If the area where the trailer passes over has shrubs or plants covering it, it’s important to have a member verify that there are no hidden obstacles that could damage the trailer before proceeding).
While in Virginia providing tiller training for the Fairfax County Fire & Rescue department I took some pictures to illustrate this point. Passing the trailer over tight roundabouts or medians in the road allowed us to successfully navigate around these obstacles. (Click to enlarge)
In my first due response area in Seattle, it’s not uncommon for us to float the trailer over a curb to successfully navigate around a corner. Our residential neighborhoods can be extremely tight, with cars parked on both sides and with traffic circles/calming circles at the intersections. With a compartment under our trailer, we would not be able to navigate these corners. (Click to enlarge)
On this corner, we were presented with a unique obstacle as we navigated around this turn. This entire street is lined with stone cobble markers lining the curb. What you can’t see in the pictures is that there is a car parked on the corner making it a very tight turn.
We were required to pass the trailer over these stone cobbles to successfully go around the corner. You can see how close the bottom of the outrigger passes over the top of the stone cobbles with barely an inch to spare. Again with a compartment under the trailer this turn would be impossible without completely ripping the compartment off. (Click to enlarge)
Wheel chocks are sometimes placed under the trailer compartment. I do not recommend this based on the above information. Here are a couple examples of a good location that is both out of the way and gives the driver easy access to the wheel chocks