I see a lot of older 0-4-0 and 0-6-0 switcher with slope bach tender. The USRA 0-6-0 had most time no slope back tender. I did never find a larger 0-8-0 switcher with a slope back tender.
How come the better visibility for the cab crew during backward switching became less important about 1915? Was the need for more water capacity so urgent at that time?
The slope-backed tender was an idea that seemed good in theory, but proved less than wonderful in practice.
Consider that the normal tender has a cistern (water tank) with vertical sides, and very llittle stress on the deck. The sloped rear deck of the supposedly high-vision tender was subjected to the pressure of sloshing (And, when recently filled, standing) water, and therefore had to be built and maintained to a higher standard.
Then, too, the visibility wasn’t improved that much. The coal bunker was still in the way of seeing across the tender. Crewmen in the cab routinely leaned out the windows to see what was going on, both ahead of and behind the locomotive.
By the time the USRA finalized its designs for switcher tenders, it was realized that lowering the sides of a normal cistern provided the same water capacity and almost the same visibility as the slope-back tender. The same was true of a Vanderbilt tender with a narrow tank and low walkways. Slope-back tenders faded into history as the locos so equipped were either phased out of service or received new tenders. I believe that only the PRR was running slope-back tenders (on their smallest switchers) by WWII.
Interestingly, the Japanese side-tank locos built in the '30s and '40s had the forward ends of the tanks sloped down, and the C56 class 2-6-0 (which was a C12 class 2-6-2 with a larger, separate, bunker and cistern) had a downright strangely-shaped tender - the rear cross-section was a thick inverted T. While it looked like a typical American slope-back, the rear deck of the cistern (same width as the coal bunker) was parallel to the rails at the level of the front deck adjacent to the cab.
A not uncommon arrangement was to have a narrowed fuel bunker and not-too-high rectangular water tank to improve rearward visibility from the cab. A small-diameter, purely cylindrical tender (such as SP used behind some 0-6-0 switchers) should have provided even better visibility.
Mark
“Chuck” wrote: “Slope-back tenders faded into history as the locos so equipped were either phased out of service or received new tenders. I believe that only the PRR was running slope-back tenders (on their smallest switchers) by WWII.”
In fact there’s quite a list of railroads that were still using switchers with slope-back tenders during and after the Second World War. It includes, besides PRR, AT&SF, B&O, GN, IC, L&N, UP, WP, and probably others. And while large 0-8-0 switchers with slope-back tenders were rare, they did exist, on the B&O to name one road.
The main reason for using rectangular instead of slope-back tenders was water capacity. That visibility was still a concern is illustrated by the way roads receiving USRA 0-6-0 and 0-8-0 switchers with standard tenders almost universally modified them with narrower fuel bunkers.
So long,
Andy
The PRR had a C1 0-8-0 at Washington DC that ran on oil that had a huge slope back tender. With the exception of the USRA 0-6-0 B28s class all switchers had slope back tenders.
Ma&Pa ran their sloped back tenders on 0-6-0 switchers until they were scrapped on the line in 1956. Like all but one of their steamers (the last 2-8-0, #43) they were purchased before WWI.
Enjoy
Paul
Thank you all for the detailed answers
Next Topic: slope-back locomotives!
Dave Nelson