Can somebody tell me why the headlight position moved more and more downward after 1910? Until 1910, almost all steamers used to have their headlight positioned on the top of the smokebox door. But after 1910, most roads started to move it to the center of the smokebox door. Why did this happen?
In many cases like on C&O, SP and GN, the headlight was positioned not in the center but a little below of it or in the lower half of the smokebox door. Only very few roads like Soo Line for example had the headlights positioned in the upper half of the smokebox door or just a little above the center. Any explainations why it was more popular to move the headlight to the lower half than the upper half?
Some things that could influence placement:
Ease of access:
Old headlights had to be filled up. All headlights needed their lenses cleaned.
Less liable to be damaged:
The higher up a headlight is, the less likely it's going to be damaged by things, large and small, that are hit. Considering the size and implied fragility of early locomotive headlights, this might account for the early high placement.
Beliefs about lighting:
I'm not sure, but I think some people think the higher a light is, the farther the light "throws". Which is kinda true, but when the light is above the height of the engineers eyes, that thrown light is useless to him. 'Cause he can't "see" it. When the light is below the height of the engineers eyes, it will create shadows that are visible to him, which may aid him in visual recognition.
Aesthetics:
It just looks BETTER placed HERE.
Ed
Thank You.
The big, boxy vaporizing oil headlights were rather fragile, so they were fastened to fixed structure above the smokebox door. The latter had to be opened frequently, and the process wasn't gentle.
The same was true for the later carbide and carbon-arc headlights, which don't like casual bumping.
Once headlights went to incandescent bulbs that vulnerability went away, and headlights could be mounted anywhere from the top of the smokebox (later PRR) to a foot off the pilot deck (some C&O), with somewhere near the center of the smokebox door perhaps the most popular.
OTOH, there were a LOT of locomotives (including a few in North America) that could NOT have headlights centered on that door. They had the 'busted clock' handles that secured the door centered on it, and that location was NOT negotiable.
Chuck (Modeling Central Japan in September, 1964 - with internal smoke box door locks secured by the 'busted clock')
As mentioned, a low or centered headlight on a very small locomotive could be damaged by an obstruction on the tracks, and if it was a large one (as in the ancient days) it might obstruct access to the pilot deck. Keeping it high avoided these problems, and allowed a worker to ride the pilot deck without blocking the light.
As locomotives got larger, and smaller electric headlights came into vogue, it became practical to mount the headlight at a lower level, such as the boiler centerline. Since the loco was bigger, it was still possible for a worker to ride the pilot beam without obstructing the light beam. Many headlights were mounted at or near the centerline, but many others were mounted a few inches higher or lower. This seems to be a matter of the preferences of the Motive Power Dept. of the individual railroad. The Operating Department probably wielded some influence here. A lot of roads, such as PRR and B&O, held onto the high position for a long time. B&O went to centered headlights on Pacifics and Mountains and a few 2-10-2's in the 1940's and 1950's, but PRR never did (except for streamlined engines, of course). It was natural to mount headlights on the pilot beam of Articulated locomotives so that the light beam could follow the curves. I have never heard a good explanation for C&O's preference for the low position. Maybe they thought it was important to illuminate the rails themselves as opposed to the generall overall right of way. The idea may have come from the low headlight position on Articulateds, but I haven't seen this verified.
Tom
To add something briefly to this discussion: consider the PRR poatwar 'beauty treatment' This ivolved moving the generator to where the headlight had been, and using a smaller headlight housing up where the generator had been. Looked like hell to railfans, but made generator radjustment and repair MUCH easier.
RME To add something briefly to this discussion: consider the PRR poatwar 'beauty treatment' This ivolved moving the generator to where the headlight had been, and using a smaller headlight housing up where the generator had been. Looked like hell to railfans, but made generator radjustment and repair MUCH easier.
And, either way, distinctly unusual, since generators were almost always placed just ahead of the cab.
If this "cab" location were used on a locomotive with a Belpaire firebox, then a maintenance worker would have a swell flat place to sit while working on the generator. That's what you got on the GN.
7j43kAnd, either way, distinctly unusual, since generators were almost always placed just ahead of the cab.
I can't prove this, but much of the importance involved reliable power to run cab-signal and ATC equipment, with equipment often located up near the pilot beam. Might be easier for a normal craft to climb a normal distance where there are handrails, and not have to lug tools etc. up onto narrow running boards and then climb ladders to do something like adjust brushes.
Did GN have similar need, or were their generators as much for cab lighting as for headlights and markers, with wiring forward cheaper than piping back to the turret?
Ah, but once you got up there, the view was gorgeous!
An interesting theory about the reason for forward placement. Did I-1's have cab-signal/ATC? B-6's? 'Cause they had the forward mount generator. GN did not have either cab-signals or ATC. Looking at plans of the T1 (which did have cab-signals/ATC), it appears to me the generator was moved back to a position ahead of the cab.
I think the reason the generators were placed on the firebox ahead of the cab was because it was a short run for the steam line back to the turret and the controlling valve. Also, it was a short electrical run to the cab where various fuses and switches could be placed.
The only reason I can come up with for placing the generator near the headlight is because it is the most critical electrical user. And if you have less confidence in making a long run of that new-fangled electrical wiring than you do a steam supply pipe, it could make good sense.
Of note, there was not a railroad stampede to convert to the Pennsy approach. So I doubt it was a lot superior. And, of course, Pennsy did what they wanted because they were the Standard Railroad.
Well De Luxe, I'd say one answer is in the picture you use as your icon on this website. As railroads began putting feedwater heaters on engines, often mounted in front of the smokestack, or sticking out over the front of the engine, there wasn't room to have the headlight there anymore.
NDG Changing a headlight bulb up high could be tricky on a high nose Road switcher, esp the garbage can type.
Not familiar with the term garbage can. Is that the light or the switcher?
Henry
COB Potomac & Northern
Shenandoah Valley
Thanks, if you don't ask you don't know.
The CNR, and probably some other roads, too, used what was known as a Dirigible headlight on some of their steam locomotives. This was a steerable headlight, with some info on it HERE
Wayne
Thank You, Again.
Wayne:
Fascinating word! I was aware that lighter-than-air "Dirigible" Airships got their name because they were essentially balloons that could be steered. But I never thought about other uses of that word. Checking my ancient (1960; 2200+ pages) Webster's Unabridged, there it is!
A Dirigible headlight! Who knew?
Tom,
Slightly OT, but the first torpedoes with screws aft and warhead forward were called, "Dirigible torpedoes." Prior to that, the torpedo was a moored naval mine, as in, "Damn the torpedoes, full speed ahead," (Adm. Farragut, Mobile Bay.)
About generator location - my two favorite 4-8-4s (N&W J, NYC Niagara) carried their generators under the left running board just forward of the firebox.
And then the strangest choice of headlight location - the D&H 4-6-6-4 with the headlight imbedded in the center of the smokebox door, lens almost flush. The same looked good on their 4-8-4, but an articulated?
Finally, the later N&W engines went from backup lights (reverse headlights) on the tender deck to backup lights imbedded in the cistern, to avoid damage from the canvas aprons on their water cranes.
Chuck (Modeling Central Japan in September, 1964 - with headlights on top of smokeboxes)
Slightly more OT, but I am wondering why SP put an extra generator on their GS's. Or was it two extra?
SP guys??????
C&O is a hard road to follow on headlight placement.While the majority was mounted on the pilot deck there are photos showing some with headlights mounted in the center of the front of the boiler while some switchers had high mounted headlights. Even some 4-8-4s headlights was located different places.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
7j43kI am wondering why SP put an extra generator on their GS's.
Two extra: one for the Mars light, and one for the ECP braking system. Yes, a total of three.