video of a deuce with air brakes

[fleetmech]

Cost must have been the driver.

The 5 ton from the same period had air brakes right? They must have decided the smaller truck did not need the braking system of the larger which likely cost more to install. This system is simple and has fewer components perhaps.

I believe the early 5 tons had the same air over hydro system we have, but I personally am not sure. HDN mentioned that they switched to full air with the later 939 series, but those are outside my current wheelhouse...

Im not aware of any other major users of this axle design. Assuming that they are just updated versions of the basic principle Rockwell had been building for the Army for years, it sort of makes sense that no one would find value in re-engineering them. With the demise of gas engines and their vacuum supply, I suppose they switched to this air booster system instead. The air booster would also gave them the ability to hook to air brake trailers if necessary.

As an aside, I've watched some other foreign truck videos and apparently massive hydraulic drum systems are still a thing in other parts of the world. I have seen some shots of massive Hino (and others) tri-axles with juice brakes.

 

[dmetalmiki]

Air brakes had been in use on railroads since the 18...50s' I think, and were greatly improved by Westinghouse in the 1870's or so. They were already well established in the trucking industry by the early 50s, and definitely should have been on the table for the design of any truck this size. The system we have though, was not totally out of left field for the time. I have seen old (think Wabco old) equipment with similar systems. The brand name commonly seen with those systems is Midland.

As for submersion, I can't see any issues that couldn't be resolved easily. The base air system would be unchanged, snorkeling off the intake, and the only alterations would be: a treadle valve(brake pedal and master control valve), two or maybe three quick release valves, and the brake chambers themselves. I have never run air brakes under water myself, but I should think they would work ok. After all, outback truckers and emergency vehicles the world over get run in some pretty wet conditions with no apparent ill effects. But, there could be some places that you wouldn't want water in. Adding a few gaskets and NPT bungs to QR valves and maxi chambers for a set of fording kit pipes would be kiddy engineering compared to the complexity of the airpack alone... at least thats my opinion.

Its a stretch, but I can almost see a bigger concern with the arctic use these trucks were supposedly able to handle. In the age before air dryers, moisture in the lines could be a major concern.

I can't put a lot of stock in any of the 'cons' of air brakes though, at least from the military's perspective, since the trucks as they actually exist still need adequate prep and after care for submerged and arctic use, so a slight difference in what type of maintenance shouldn't matter.

Yet Russian trucks navigate all over Siberia through muck, mud, DEEP Ice and snow and water up to the windscreen......With.. Full .'Air Brakes'.