Blast Path The lower door is where the rocket exhaust would flow into the blast pit during initial launch. The upper doors would vent the rocket so the erector and other equipment in the building would not be (as) damaged. Similar Images ...based on the tags: clouds, ditches, doors, launchpads... Jef throws open the back door of an alley for the trailing photographers and historians. Inside the office was a small furnace and a collection of mechanical belts. You can see “SERVICE AT COST” and “POOL 168” in the background. National Mine and its rockhouse (?) as seen from Mammoth Hill. From this angle, I am fairly certain this was a crushing and sorting house. The bottom looks like it has two aerial tram doors as well. A bumper sticker with the usual tagline. Note the detail on the radiator! The back wall of the ballroom, showing water-warped floors. Bayard Sugar Mill, as seen from the old power plant David Aho pictured. This dock goes between loading bays (see glass brick walls) and the railroad. Sleeping bags mark this former courtyard as a crash pad for the local homeless.