booster exhaust on a Hudson

Hi All,

Does anybody know how the booster exhaust on a Hudson (small smoke stack in front of the main stack) works? I've seen vids of steam pouring out when they're running but nothing when they're sitting still. Any info or even a book to look at would be great. I've done some research but came up empty handed.

thanks,
Joe

A popular misconception is that the smaller stack immediately forward of the main stack on the J-1e, J-2 and J-3a Hudsons is just the booster exhaust stack. Actually, this is an auxiliary stack. On the J-1e and J-2 engines, the booster exhaust was vented here but there was also additional piping routed to this stack from other appliances on the engine such as the Elesco feed-water heater, etc., resulting in a thicker auxiliary stack than that on the J-3a Hudsons whose booster exhaust was actually routed to the rear tender deck. There have been no photos or drawings showing booster exhaust piping on the J-3a locomotive itself. [Central Headlight, Volume XII, No. 4, 4th quarter 1982]

According to Charlie Smith, while this part of the locomotive was commonly called an “auxiliary stack,” the NYC engineering office classified this as a “pipe casing.” Additionally, this casing was closed at the top with holes for the piping directed there. [Central Headlight, Volume XIII No. 1, 1st quarter 1983]