Fred M CainIf you saw a picture of an SP semaphore with a green, amber and red lens all on one blade, I'd tend to suspect that the quality of the picture might be questionable but I can't prove that.
That middle aspect in the right-side head in the picture sure does look like a different, and more amber, color though... enlarge the picture and see.
It does appear there were 45-90 LQ heads made, with one of the last of them apparently in Memphis. I do not have pictures but knowing they existed will help with the search.
timz <SNIP> Dunno if any US railroad tried 0-45-90 lower-quadrant semaphores as block signals.
<SNIP>
Dunno if any US railroad tried 0-45-90 lower-quadrant semaphores as block signals.
Far as anyone knows, no US railroad used block-signal semaphores showing three aspects at 30-degree increments of blade angle. Lower-quadrant blades were almost always two-position, 60 degrees apart; the exception could be two-position, 90 degrees apart.
jeffhergert Here's a picture, first one of the article, showing a lower quadrant with red, yellow, and green aspects on the SP. Railroad Signals: Search Lights, CPL's, And Semaphores (american-rails.com) Jeff
Here's a picture, first one of the article, showing a lower quadrant with red, yellow, and green aspects on the SP.
Railroad Signals: Search Lights, CPL's, And Semaphores (american-rails.com)
Jeff
I have read about 3 position LQS having a fully vertical position that could sometimes be hard to read blending in with the mast. But on a 30-60-90 configuration, couldn't the 30 and 60 be confused as well?
Balt, doesn't this post go in the 'Then and now' thread???
Overmod timz The SP single-blade semaphore has two aspects. The three lenses are just for show. You miss the point. In the picture, look at the left-hand and right-hand spectacle positions over the lamp relative to the blade angle. I asked about 30-60-90 mechanisms and since these are obviously spectacles corresponding to those angles it would be fairly safe to assume the mechanism parts are, too. (Yes, technically that should probably be a 90-60-30 in lower-quadrant use, but it's the incremental angle in either case that's significant)
timz The SP single-blade semaphore has two aspects. The three lenses are just for show.
You miss the point. In the picture, look at the left-hand and right-hand spectacle positions over the lamp relative to the blade angle. I asked about 30-60-90 mechanisms and since these are obviously spectacles corresponding to those angles it would be fairly safe to assume the mechanism parts are, too.
(Yes, technically that should probably be a 90-60-30 in lower-quadrant use, but it's the incremental angle in either case that's significant)
Seemingly all TV, both over the air and cable channels, have synchronized their commercial minutes so channel surfers go from one commercial on a channel to another commercial on another channel; with the hopes that they will return to their original channel as they will be unable to find anything more interesting. Somehow this even tends to work on sporting events when you would think the 'breaks in the action' would generate less than predictable commercial slots.
When I was a season ticket holder of the BALTIMORE COLTS, there was a individual that would walk on the field in what appeared to be a fireman's duty coat - he was the identifier to the game's referee that a commercial was being taken and for play to be held up. In the September & October games it was a minor inconvience. In the bitter cold and winds of November and December games one wanted to get him off the field post haste.
Never too old to have a happy childhood!
timzThe SP single-blade semaphore has two aspects. The three lenses are just for show.
I can't imagine these were designed with three positions for lenses without corresponding 'mechanism' for those positions. That isn't to say SP used all of them; it's not uncommon to find spectacle positions 'blanked' with plates where particular railroads did not use corresponding positions. But there is no position on these spectacles for an aspect corresponding to 90 degrees with the given blade attachment style, although I think I have seen plates with four openings in a couple of places (don't ask me where; I'm not a semaphore guy).
The SP single-blade semaphore has two aspects. The three lenses are just for show.
Thanks, Jeff.
While we're here, who used 0-30-60 lower-quadrant aspects?
That's a question -- were single-blade lower-quad automatic block signals always two-position, not three? What objection is there to 0-45-90 counterweighted blades?
(By the way: who used 0-90 lower-quad blades, besides N&W?)
jeffhergertI always thought that lower quadrant semaphores were counterbalanced to go to horizontal if something fails
I'd be nervous even about a train-order signal using lower-quadrant vertical as 'proceed' but as you noted, it's their sandbox.
Overmod There is another point here, though, which is that a 45-degree mechanism couldn't safely display three aspects on a lower-quadrant semaphore. If the power goes out the blade will fall under gravity to the same indication as full,and that's as bad as having lunar white, the color of fallen-out glass roundel, being full speed ahead... For this, if you want three aspects, use a 30-degree increment head. Horizontal is still stop, you have distinguishable levels at the two angles... and straight down is still 'most restrictive you can get' -- put a red in that fourth position if you want nighttime redundancy.
There is another point here, though, which is that a 45-degree mechanism couldn't safely display three aspects on a lower-quadrant semaphore. If the power goes out the blade will fall under gravity to the same indication as full,and that's as bad as having lunar white, the color of fallen-out glass roundel, being full speed ahead...
For this, if you want three aspects, use a 30-degree increment head. Horizontal is still stop, you have distinguishable levels at the two angles... and straight down is still 'most restrictive you can get' -- put a red in that fourth position if you want nighttime redundancy.
I always thought that lower quadrant semaphores were counter balanced to go to horizontal if something fails.
Some lower quadrant semaphore train order signals had clear with the blade at or near vertical.
There is another point here, though, which is that a 45-degree mechanism couldn't safely display three aspects on a lower-quadrant semaphore. If the power goes out the blade will might fall under gravity to the same indication as full,and that's as bad as having lunar white, the color of fallen-out glass roundel, being full speed ahead...
Loco2124 If lower Quadrant semaphores were used to display only 2 aspects, why do they have 3 spectacles?
If lower Quadrant semaphores were used to display only 2 aspects, why do they have 3 spectacles?
Lower quadrant semaphores could display all three aspects. Depends on what the railroad wanted...
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The spectacle is part of the counterbalance. Rather than have two different sizes of parts (including motor drives) it might make better sense to 'standardize' on three aspect plates and simply blank the unused aspect position or leave its glass out.
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