This one's for Gary S.

[doctorwayne]

It certainly makes sense to get some use out of the wasted heat. But most steam locos I see in photos don't have the apparatus on the nose. Were there other places that these heaters were installed on a loco?

The Elesco heater bundle (where the actual heating took place) usually was located atop the boiler, as shown in the photos, although I've seen them behind the stack, too. Another common location was on the pilot deck: the loco shown below has its heater atop the smokebox but it could have been placed below the smokebox where the air tank is located -


There are other examples shown in the link posted HERE

"Only about 12% to 16% of the exhaust from the cylinders is required, leaving a remainder amply sufficient to take care of the draft requirements without nozzle adjustment."

What exactly does that mean?

Normally, the spent steam from the cylinders was exhausted out the stack (along with the smoke). In fact, the exhausted steam is still expanding, so it's propelled up the stack rather forcefully. This tends to draw the smoke and hot gases through the flues within the boiler, which in turn, draws combustion air into the firebox. When a steam loco is at rest, with no cylinder exhaust available, a blower is available to aid in draught creation, but it, of course, requires steam to operate. So essentially, the feed water heater requires only a small amount of the total exhaust steam, leaving an ample supply to maintain a good draught.

Further economy is obtained by reclaiming the condensate.

I assume that in the original engines, the steam was exhausted out of the cylinders into the atmosphere. The condensate reclamation took the exhausted steam and condensed it back to liquid and put it back in the boiler?

A closed system for the water to steam to water would have certainly been possible... with hardly any loss of water, negating the need to stop for water at all. But I suppose the energy requirements to move that water around made it less efficient than to just exhaust it into the atmosphere?

While it's generally not considered feasible to attempt to reclaim the spent steam as condensate, the fact that it's already captive in the fwh system requires very little additional effort. In South Africa and, I believe, Australia, some railroads running through desert areas with little or poor-quality water available did use condensing systems to reclaim much of the water from the exhaust steam.

Wayne