Does anyone know the distance from the track to the bottom of a telltale?
Thx
That distance varies. It is the distance from the track to the lowest point of the portal that would be in direct contact with a car or load passing under it.
The point being, the TellTale gives the indication to the fact that the car or load will or will not clear or be able to enter the portal without damage to itself or the portal.
I do not know if it is true or not , but I have read and seen pictures protraying that they also warned roof walkers on the cars that there is a low overhead clearance approaching that will likely knock them off the car if not heeded.
Johnboy out.......................
from Saskatchewan, in the Great White North..
We have met the enemy, and he is us............ (Pogo)
Here's what the B&O has to say about it...
The telltale was provided to warn employees standing on the roof of cars to make them aware of overhead clearances. Of course, they disappeared as part of the removal of roofwalks beginning in 1966 and supposed to be completed by 1974 although there were still some stragglers by the early 1980s.
Hope this helps, Ed
The line where it says the cords must "project at least six feet below the lowest point" of the conflicting overhead structure is key here, but raises other questions. So long as the cords clear typical equipment overall heights passing below, it's good. But one would think this would be at least foru to five feet above roofwalk height, otherwise there would be a tendency to knock employees off the car tops. Likewise, the cords shouldn't be so low as they drag across the tops of equipment.
Maybe clearances were such that there was never a situation where this became a problem, though?
Mike Lehman
Urbana, IL
mlehmanThe line where it says the cords must "project at least six feet below the lowest point" of the conflicting overhead structure is key here
Mike, It's hard to read but that note says six INCHES below lowest point of overhead structure...
Ed
Ah, OK, that's a little different. Still makes me wonder if any clearances were such that it presented a problem of the telltale being too low to be safe in itself.
I have heard from old timers that they smarted when you got whacked with them, especially in the rain or cold weather but that's their job. Better a cold, wet rope than a hard, iron bridge!
I'm still trying to figure out the hinge affair and the phantom line on the drawing showing the arm in a lowered position? The oak pole is for untangling the 3/8" bell rope and that framework with the wire mesh is none too flexible. I could see making it so it would swing away if struck very hard but dropping down doesn't appear too clear to me.
I'd say if you were a 6' 4" brakeman you would have more of a tough time than a 5' 3" fellow would...
On the Chicago & North Western they were known as Whip Guards - and the whips were made of No. 9 galvanized iron wire so yeah, that would smart. The drawing reproduced in the C&NW Historical Society's Standards Book says the whips were to be "of length to suit conditions" which is not helpful except it is clear there was no one length, and the drawing also says the height was to be 17'6" "or as much less as is required so that the ends of the whips shall be not less than 6" below the lowest projecting point of the structure to be guarded." It also says the Whip Guard was to be placed 300 feet from the structure to be guarded.
Interestingly the drawing also alludes to state laws that placed requirements on Whip Guards: " in states where specific laws govern, place whip guards where vertical clearance of any bridge or tunnel is less than standard clearance for bridges." The drawing is dated 1933.
If the end of the whip was to be not less than 6 inches below the lowest projecting point of the protected structure. then it wasn't just a matter of tall versus short guys who would feel the sting. Thin guys laying face down on the top of a car might be spared but the fatter guys would want to be between cars and in a hurry too if they felt the whip.
Dave Nelson