Take a look at the top side of water tank outside the pigeon roof , there are brackets cut off . These were to support the front bunk of a "preload trailer" when a trailer reload was used to load the trailer "piggy back" on truck at log dump and the log loader unloaded trailer at the loading side in the woods . This truck was an early "Preloader" . Up until the early 1970's BCFP Renfrew Div. had a couple of Washington TL 15's loading with "Tongs", all the trucks required the trailers to be unloaded by the log loaders using the Tongs or a set of "Lifting Hooks" hung on one side of the Grapples for that purpose . In the Spring of 1967 I was "Chasing & 2nd Loading" on a Steel Tower side . A part of my job was to climb up on the trailers to hook the two trailer lifting straps on to the lifting hooks on grapple . One time I had hooked up the lifting strap and was stepping off the truck into the clear , when I heard a loud crash above me . When the loader had started lifting up the trailer , the "Boom Line" had broken and the "Heel Boom " had dropped on the trailer bunk . And there it stayed until another "Boom Line" was brought out from camp and installed on loader .