. . . because I've never seen it asked before. Nonetheless, I'm at the point in my hobby where I've got to know:
How do trolleys change tracks? The lines don't have switches. What, if anything, must the motorman do to make a trolley car, say, diverge left instead of staying on the main track?
Inquiring minds, etc. . . . - a. s.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Many trolleys/streetcars used single point switches and had a frog for the other side. The point when diverging or acting as the guard rail when going straight forced the other wheel through the frog correctly. The overhead was not a problem for pantographs, for poles I'm not sure how that was handled. For underground systems where the wire was between the tracks below street level, the motorman had a handle to raise and lower the slider and I think they coasted through areas where it had to be raised. For third rail systems where a wiper was needed I think they coasted also.
Enjoy
Paul
Wrong on the conduit system. The double faced "plough" could move from side to side, but not up and down. But you are correct about coasting through. Interestingly enough, since nearly all crossings (not switches) on conduit lines were double track for both lines, since conduit was only used in built-up areas with heavy transit service, there was polarity reversal when going though the crossing, which didn't matter with series dc field-coil motors. There was a slight horzontal taper of the power rails on each side of the conduit slot where the power rail was interrupted, so the spring shoes on each side of the plow would engage the rail without any problem after going through the gap. Although the plow could move from side to side (indeed, in London all the way to the side of the tram and more to coast to a center slot between the two tracks at the point where the switch from conduit to overhead wire was made, thus not requiring the "plow pits" for removal of the plows at such locations in New York and Washingnton) the plow was guided by the edge rails that could be seen in the street and had centering springs (like the front trucks of a steam locomotive) so that at a switch, with the right conduit design, the plow went in the same direction as the streetcar's wheels. The edges of the plows in contact with the edge rails of the conduit were about ten inches or a foot in length, thus easily spanning the approximately three-inch gap at crossings. Visually, on the street, cable-car switches and crossings aren't any different, but the grip is an entirely different matter, mechanically, than the plow.
London's conduit trams had the plough carrier attached to the bottom of the car body, but New York and Washington had them attached to the truck bolster. Side-to-side motion was allowed to be greater on the New York plough carriers than the Washington cars, so a New York car could run on coundit in Washington, but not the reverse, except on a few selected lines.
Although nearly all Manhattan assigned streetcars (two short lines, one for New York Railways and one for Third Avenue Railway, a total of about ten streetcars with three or four in service at any one time) were without trolley poles, equipped only for conduit operation (until 1947 when some got trolley poles for a 1-1/2 year further service in The Bronx), by the time of WWII all Washington streetcars were equipped both for conduit and trolley wire. If memory serves, around 1935 the last of the center-entrance (double-end, two-man-center doors only) cars were retired in Washington, and some of these may have been conduit only.
On trolley-pole streetcar lines, and you can check this out at a trolley musuem, the "frog" where two wires come together, is always beetween the movable points or point where the rails start diverging, and the frog where rails cross in a given switch. With the usual springing of the trolley pole at the base, and the angle of its flange with respect to the grooves, the trolley wheel or shoe will want to return toward the base, not away, and thus will pick the grooves in the shoe that cause it to go in the same direction as the car. Because of the maneuverability of trolleybuses, movable point overhead frogs in the wire are usual, and this would also be the case where trolleypole trolleys and trolley buses share wire.
Okay, if I am assimmilating this info properly, on a streetcar (trolley) line, the motorman has to coast thru the intersection to stay on the main.
If he must diverge, though, he will power into the realm of the switch and the fact of his power being engaged will send the switch in the proper direction.
Sometimes I am amazed how smart people were in 1910.
But if I'm still missing the point , please let me know! - a. s.
daveklepper wrote: On trolley-pole streetcar lines, and you can check this out at a trolley musuem, the "frog" where two wires come together, is always beetween the movable points or point where the rails start diverging, and the frog where rails cross in a given switch. With the usual springing of the trolley pole at the base, and the angle of its flange with respect to the grooves, the trolley wheel or shoe will want to return toward the base, not away, and thus will pick the grooves in the shoe that cause it to go in the same direction as the car. Because of the maneuverability of trolleybuses, movable point overhead frogs in the wire are usual, and this would also be the case where trolleypole trolleys and trolley buses share wire.
dd
Somewhat along the same lines of forced application of electricity, has anyone here besides me seen a CTA workers "sting" a car with an electric prod? When the L car can't coast thru an area with no shoe on either side, a worker grabs an instrument with a long, long wand, and Zap! the car jolts foward a little. The empowering device looks to me a little like the wash wands in those do-it-youself car washes.
Stinging is considered unsafe but I don't think anyone found a way around the practice. Stinging is especially prevalent in the winter months and, while not frequent, most of the times I've seen it in use is just north of Belmont/Sheffield station, probably because the diverging-left Ravenswood line tracks call for a lot of frogs and switches and places without shoes.
Someone please correct me if I am wrong, but doesn't the CTA maintain a manual tower there? The lines still use the manual block system, or most of them. The CTA is crumbling not only from general lack of attention but plain old archaism and decrepitude.
Replying to diDance, this is a matter of maintenance. The concept works if the trolley frog is level. If the expansion or contraction of the span wire at the frog on one side is greater or less than that on the other, the frog will have a slight tilt to it and the wheel or shoe will go to the higher side, regardless of which way the streetcar is going! Or the frog may be pulled laterally off its "center" (actually not quite center) location. So trolley wire at switches requires inspections. Obiviously, equipping cars with pantographs or bow collectors is an obvious solution, which is why most systems have gone in that direction.
The North Shore had the very best maintained trolley wire, up to its very last hour of operation!
Regarding stingers, did it on occasion myself at the Shore Line Trolley Museum in Branford and East Haven Connecticut, where not all tracks are "wired."
daveklepper wrote: Replying to diDance, this is a matter of maintenance. The concept works if the trolley frog is level. If the expansion or contraction of the span wire at the frog on one side is greater or less than that on the other, the frog will have a slight tilt to it and the wheel or shoe will go to the higher side, regardless of which way the streetcar is going! Or the frog may be pulled laterally off its "center" (actually not quite center) location. So trolley wire at switches requires inspections. Obiviously, equipping cars with pantographs or bow collectors is an obvious solution, which is why most systems have gone in that direction.
thanks - your descriptions of the maintenance problems jibe with my recollections that most trolley poles came off in the winter when temperature and ice really stress the wires.
al-in-chgo wrote: Somewhat along the same lines of forced application of electricity, has anyone here besides me seen a CTA workers "sting" a car with an electric prod? When the L car can't coast thru an area with no shoe on either side, a worker grabs an instrument with a long, long wand, and Zap! the car jolts foward a little. The empowering device looks to me a little like the wash wands in those do-it-youself car washes. Stinging is considered unsafe but I don't think anyone found a way around the practice. Stinging is especially prevalent in the winter months and, while not frequent, most of the times I've seen it in use is just north of Belmont/Sheffield station, probably because the diverging-left Ravenswood line tracks call for a lot of frogs and switches and places without shoes. Someone please correct me if I am wrong, but doesn't the CTA maintain a manual tower there? The lines still use the manual block system, or most of them. The CTA is crumbling not only from general lack of attention but plain old archaism and decrepitude.
CTA still has a manned tower at Clark Street. The rapid transit system is also protected by automatic block signals systemwide, either wayside signals (mostly on the downtown subways and the Congress line) or cab signals. As far as the use of stingers, CTA has an elaborate set of instructions designed to lessen the risk in an inherently hazardous practice.
A lot of trolley lines used spring switches, which automatically favor one route but will permit a car to pass through from the other route. Frequently found at the end of the line, or at places on double track at the end of routes, where the pole(s) would have to be reversed for the return trip.
I recall, as a boy, seeing streetcar motormen throwing the single point of a facing-point turnout with a tool something like a crowbar with a long handle. This at an intersection where two routes diverged to go to separate end terminals. The matching turnout, which was always taken trailing point, didn't even have a moveable point.
Chuck (modeling Central Japan in September, 1964)
wjstix wrote:In early streetcar days, the motorman and/or conductor had a long turning device, kind of a long pole or crank-lever. The working parts of the turnout were below the street. The motorman reached out of the window and inserted the pole device into a hole in the street before the turnout, and then could manually turn the turnout to the direction he needed to go.
Ha,ha, in Romania we still use a lot this sistem.
About automatic switehcers: unleass here, in Bucharest the sistem goes like this. On the wire, before the switch, an kind of slide is mounted. When the pantograph touches the slide, it operates the switch. If the controller is on 0 position or the accelaration pedal isn't pressed, the switch remains on foward posiotion, if the controller is on 1 or 2 position, or the acceleration pedal is pressed then the switch is change for right or left direction. P.S. In Romaia most streetcars have are controling the speed with the help of a controller. The only P.C.C. type streetcars are the Chech "Tatra".
The sistem is also used by the trolleybuses (all trolleybuses swtiches are automactly operated), only the slide construction is different. Newer trolleybuses usually don't use the acceleration pedal to change the switch - they have an special buton for it.
I'll try to put some pics with the sistems.
al-in-chgo wrote: . . . because I've never seen it asked before. Nonetheless, I'm at the point in my hobby where I've got to know: How do trolleys change tracks? The lines don't have switches. What, if anything, must the motorman do to make a trolley car, say, diverge left instead of staying on the main track? Inquiring minds, etc. . . . - a. s.*******************************As a technical instructor back in real life, one of my first comments to students was that the only dumb question is the one that never finds voice.As has been mentioned in several responses, trolleys do have track switches, which are used to diverge a car onto an alternate route or line, and they function much the same way as any rail switch by guiding the wheels in the desired direction.The track switches that are hand-thrown may use a "crankover" form of operator, but most manual track switches were set up with a toggling spring arrangement to hold the point at one position or the other, and the point was thrown over by simply prying it with the switch iron using a twisting motion. Electrical throws operated in different ways, depending on the manufacturer and the system using them. Some locales were power on for the primary route and power off for the secondary, others reversed that, still others used power off for the straight route and on for the diverging route or vice versa, some use power on the throw the switch and power off to leave it as previously set. On the conduit roads, most used a double-blade track switch with a third blade under the street slot to direct the plow to the proper line. Anywhere there was a crossing or divergence of lines, there was a short distance over which the plow was out of contact with the power bus and the car had to coast through. Once in a while, a car didn't make it and would get a push from a following car or a friendly truck driver. The wire when used with trolley poles has a device called a "frog" that allows the pole to be directed to either of the two routes diverging out of the track switch. The rail device where the diverging rails cross is also known as a "frog", whether for a track switch or a crossing. With trolley wheels, the wire frog had a long open area in the middle to allow the wheels to either turn to follow the curved route or pass straight through, but there was no guidance in that middle area. Thus, a tipped frog could cause all manner of problems. The situation is different with sliding trolley shoes, however, and the frog has a different design. Runners pass entirely through the middle of the frog, with slots for the flanges of the shoes to pass through. This type of frog is located closer towards the rail frog at track switches than is the case with frogs designed for wheels, and the shoe will reliably follow either path through the frog and without regard to whether the frog is slightly tipped. This was one of the big reasons for the conversion from wheels to shoes, plus the shoes generally were built to carry lubricating graphite blocks, which reduced wear on the wires, and they did not tend to throw arcs along the wire when under load. Trolley poles are not sprung to center. They are sprung upward to hold the wheel or shoe tightly against the overhead wire, but the trolley pole base is designed to swivel as easily and freely as possible so the pole will track reliably. The bases contain long roller bearings and some type of of thrust bearing arrangement to reduce as much drag as possible that results from the downward force from the weight and the pole springs. Any drag or limitation on the swing of the pole base can and will cause dewirements and tracking problems, including at switch frogs. Trouble can also occur if either the wheel is not running parallel to the wire or the wheel is tipped away from vertical.The trolley base is designed to ensure that the upward force applied to the pole is maintained within a five-pound variation between the pole being full down and fully raised. This tension is adjusted with the pole at full height or at not less than 70 degrees above horizontal. Doing so ensures the tension holds at all normal working heights of the pole on the wire.
*******************************
As a technical instructor back in real life, one of my first comments to students was that the only dumb question is the one that never finds voice.
As has been mentioned in several responses, trolleys do have track switches, which are used to diverge a car onto an alternate route or line, and they function much the same way as any rail switch by guiding the wheels in the desired direction.
The track switches that are hand-thrown may use a "crankover" form of operator, but most manual track switches were set up with a toggling spring arrangement to hold the point at one position or the other, and the point was thrown over by simply prying it with the switch iron using a twisting motion. Electrical throws operated in different ways, depending on the manufacturer and the system using them. Some locales were power on for the primary route and power off for the secondary, others reversed that, still others used power off for the straight route and on for the diverging route or vice versa, some use power on the throw the switch and power off to leave it as previously set. On the conduit roads, most used a double-blade track switch with a third blade under the street slot to direct the plow to the proper line. Anywhere there was a crossing or divergence of lines, there was a short distance over which the plow was out of contact with the power bus and the car had to coast through. Once in a while, a car didn't make it and would get a push from a following car or a friendly truck driver.
The wire when used with trolley poles has a device called a "frog" that allows the pole to be directed to either of the two routes diverging out of the track switch. The rail device where the diverging rails cross is also known as a "frog", whether for a track switch or a crossing. With trolley wheels, the wire frog had a long open area in the middle to allow the wheels to either turn to follow the curved route or pass straight through, but there was no guidance in that middle area. Thus, a tipped frog could cause all manner of problems.
The situation is different with sliding trolley shoes, however, and the frog has a different design. Runners pass entirely through the middle of the frog, with slots for the flanges of the shoes to pass through. This type of frog is located closer towards the rail frog at track switches than is the case with frogs designed for wheels, and the shoe will reliably follow either path through the frog and without regard to whether the frog is slightly tipped. This was one of the big reasons for the conversion from wheels to shoes, plus the shoes generally were built to carry lubricating graphite blocks, which reduced wear on the wires, and they did not tend to throw arcs along the wire when under load.
Trolley poles are not sprung to center. They are sprung upward to hold the wheel or shoe tightly against the overhead wire, but the trolley pole base is designed to swivel as easily and freely as possible so the pole will track reliably. The bases contain long roller bearings and some type of of thrust bearing arrangement to reduce as much drag as possible that results from the downward force from the weight and the pole springs. Any drag or limitation on the swing of the pole base can and will cause dewirements and tracking problems, including at switch frogs. Trouble can also occur if either the wheel is not running parallel to the wire or the wheel is tipped away from vertical.
The trolley base is designed to ensure that the upward force applied to the pole is maintained within a five-pound variation between the pole being full down and fully raised. This tension is adjusted with the pole at full height or at not less than 70 degrees above horizontal. Doing so ensures the tension holds at all normal working heights of the pole on the wire.
blue streak 1 wrote:Last time was in SFO LRVs and PCCs used power on to switch the points opposite. The trolly buses used one of two methods. For a long range wire switch a mark in the street would have a L (R) meaning power on would cause both wire switchs to go left (right). Once the electric poles went through the wire switches they would restore. Some drivers called it pulling the switchs. On street turns an offset pair of a u shaped contacts had to be contacted together (bus already turning) which provided power to both switches to diverge and once the poles went through they restored.
I am still pretty naive--only about five months ago did I learn that restoring "heritage" cars was an industry in itself, as opposed to rehabbing older equipment (Philadelphia's No. 15 air-conditioned streetcar line), or buying new (as in a Siemens turnkey operation).
All these stinging and long-reach prod techniques -- are they still even legal under today's occupational safety laws?
Another question: In the future, all commuter RR cars in USA will have non-"flippable" seats, forcing at least some of the train's passenger to ride backward if the coach is any more than half full. That's because solid seats have been deemed to be safer and the flippers are unacceptable in new equipment.
Does that apply to LRV's was well? If so, does it also apply to vintage? One of my earliest memories is seeing the St. Charles line conductor (New Orleans) stride down the aisle at terminus, flipping seats with great aplomb, and I'd kind of hate to see that habit made unlawful if not absolutely necessary. I guess I'm asking is, is vintage trolley/streetcar stock grandfathered out of any such safety stricture?
Our community is FREE to join. To participate you must either login or register for an account.