Steam & Excursion > Whistle Guards

Read a book a while back about FW&D. Several pics of 2-8-2 Mikes had a sheath of metal covering the sides of upright whistles. Any one know their purpose?

Deflect the steam from blowing back in the engine crew's faces.

Great question!

I don't have a definitive answer, but I have seen these on Canadian locos; also, the PRR used (what I call) 'whistle pans'.
The PRR versions were fitted to the horizontally-mounted PRR whistles attached to the back side of steam domes of their K4 & L1 locos (as well as others).
The PRR pans were shallow, vertically curved deflectors fitted with low sides -- the scoops concentrated the steam 'plume' of the whistle such that the steam/air flow confined the escaping steam over the roof of the firebox and back across the cab roofs.

I suspect that the the early, unconfined steam 'plumes' blew great clouds of steam down and across the PRR's Belpaire firebox right down in front of the engineer's side of the cab! So, I suspect that these 'pans' were added in an attempt to improve visibility when approaching grade crossings!

The type that you describe can provide a similar 'trapping' effect to the steam flow, but I also suspect that these shrouds were also designed to concentrate the sonic, high pitched, sound waves in the forward direction to aid in projecting the noise at grade crossings ---- maybe an attempt to give motorists better warnings!

Many whistles, without the shrouds, had the sound waves diffused in all directions --- so that at high track speeds, the warnings and grade-crossing whistle blasts were hard to discern inside vehicular trucks and autos --- ergo, the application of air horns to steamers ---- the 4449 and her sisters
(as well as the SP cab-forwards) are fitted with 'single-bell' air horns and the NYC Niagaras (6000 series, 4-8-4s) had air horns mounted high on the boiler, just ahead of the engineer's office! My suspicion is that the NYC air horns may have been subject to snow-packing and freeze-ups --- maybe they wanted to put the air horn where is was warmer???

But, again, I suspect that the shrouds that you see are for concentration of the sound waves in a forward-direction -- for (perceived?) enhanced grade crossing warnings?

What are other thoughts?

Overfire Jets

NKP 700's had these shrouds, also. I always figured that it was to help direct the sound forward to unsuspecting motorists at the next grade crossing. Most steam locos had the whistle on the fireman's side so as to lessen the obstruction of the engineer's view by steam.

whistle mounted fairly close to the cab can be painful to the ears of the operating crew.
Shields can deflect that sound forward but also cut the decibels down to a more reasonable level in the cab

Whistles mounted on the steam dome also had a tendency to dribble water with the steam. The shields kept that from being blown into the front windows and crew faces.

Posted from Android

Last year I put my Wheeling and Lake Erie 5 chime on 765 for a day. I also removed the shroud because it didn't fit with my whistle.

Not only was the noise level in the cab much louder but the the amount of steam drifting over the top of the boiler to my side increased substantially.

Now without a direct comparison with the same whistle with and without the shroud, and cannot accurately measure the increase in noise levels. The W&LE whistle is probably the loudest I have heard. It completely drowned out the Hancock 3 chime we had mounted up front.

Posted from iPhone