What is a “blind joint”? Only thing I can thing of is a joint where all the bolts are sheared off on for one of the rails so it is free to slide back and forth between the parallel joint bars.
- PDN.
[quote user=“Paul_D_North_Jr”]
Overmod
. . . I remember a story decades ago now in Trains about a solid trainload (pun not intended then, but intended now!) of beets in far-from new cars, where the duty crew sat for a couple of hours pumping but couldn’t get pressure to the point of release. . . .
It was this article in the February 1973 issue:
Battling blizzards on the Big G
working as a brakeman in the winter
by Patrick, Howard S.
brakeman
In very cold weather, snow and ice can build up on the tracks blocking points, the equipment that allows trains to move between tracks. To de-ice the ice on road, usually they will put salt. Good question that raised. Now I’m thinking is it possible for ue to put salt on the rail to melt the ice?[I]
Possible - not practical or encouraged. Salt enhances the creation of rust on metal surfaces - switch points slide on metal surfaces that normally have dry graphite applied as the lubrication - it is desired to keep the switch points and the surfaces they move upon with dry lubricants. Wet lubricants (oil & grease) attract dirt and dust and end up being abrasives not lubricants.
At control points that are operated from remote location, various forms of ‘switch heaters’ are employeed to keep the switches operable. The form of the heaters raing from ‘smudge pots’, LPG fired heaters, electric heaters, cold air blowers and any other device thought to be able to keep the points free of snow and ice.
When these means fail - MofW personnel with brooms and ice chippers come to the rescue.
MC and diningcar are two participants who will have specific discussions about what works and doesn’t work in snow and ice clearance. But before we go there, a few key distinctions need to be made.
Roads are salted because salt water freezes to (dangerous) ice at a lower temperature. Ice on roads is only severely dangerous to the extent pressure or friction can form a thin layer of liquid on the ice surface, the principle on which skates work; ice below about 23 degrees does not show this effect.
The situation of ice on the contact patch of the railhead is more complicated, in part because the thermal mass of the rail will near-instantly chill a thin film of water, but the severe pressure at the contact patch will liquefy ice on the railhead and compress it to a thin film. Using salt here, say as an additive to traction sand, would not affect the essential slip problem ‘much more than sand alone’ – and salt is hygroscopic, corrosive, and likely would lead to caking problems, one of the LAST things you’d intentionally provide in any traction-sanding system.
Meanwhile, a second serious problem is that of flangeways, for example at crossings. Here the ice buildup is to an extent that salting with NaCl won’t reach, and the practical amount of flange lifting to risk derailment is only on the order of ¾" or so. Therefore the preferred method is to use a flanger periodically to mechanically, and effectively, remove dense buildup of ice or snow (or ponding that proceeds to icing solid).
The chief danger at switchpoints (as I understand it) is not so much that the linkage will freeze and make the switch difficult to throw as that motion of the points will pack snow and ice to keep them from fully locating. This makes for a number of dangerous situations and no good ones. The bad news here is that
One other reason not to use salt on rails is that salt can play havoc with track circuits.
UP and, presumably, many other roads would reduce originating train length ahead of predicted low temperatures - varying according to predicted lows. Trains enroute would generally keep going until they might experience air problems and often reduced in length enroute when necessary. I suspect DPU operations may have improved air flow in cold temperatures. Back in PRR/PC days used to commonly have to pump alcohol through a train that stopped to set out or pick up, for example, to gets its brakes released. Often the decision is made to eliminate breaking a train line below certain temperatures. UP had its protocol for operations at low temperature ranges prescribing length and maximum speed. >
Broken rails have been a major bugaboo of winter operations, often arising en masse with the first real cold snap of a season and a common task for maintenance of way crews. Often a broken rail is passable, whereby a qualified employee on the ground can roll a train over the break at reduced speed. If the break is to such extent that it is impassable, you are done dealin’ until MofW can get on the scene, place joint bars or patch the rail. Real fun when switches are drifted in and you cannot route other trains around the break (call 1-800-dog-ctch). Flat wheels could and will tear up a piece of railroad in extreme cold and fortunately detectors make this an unusual occurrence these days, as mentioned above by BaltACD. >
In hot weather where expansion can be a problem, the proverbial sun kink, MofW is on heightened alert, hi-railing. The real danger here is that track circuit continuity is not affected as with a broken rail in most cases. Thus rules prescribe the method of train braking so as to minimize stress on the track structure during high temperatures for a given district, as well as maximum speed for various tonnages. >
Great story about the cat! I’m having trouble picturing where he was, though. Can someone shed some light on this?
It’s been a while, but I seem to recall looking up that train at the time, and the second (dead) unit was a EMD SD75I.
I suspect the cat had been hiding on top of the fuel tank, in behind the air reservoir. As this is directly underneath the engine that area would still be fairly warm and sheltered in the winter. There may also be holes in the frame large enough for a cat to climb through into the engine compartment.
At what point, if any, would ambient air temperature be considered too hot to continue operations?
Has a U.S. railroad ever shut down operations because it was too hot?
My experience has been that extreme conditions determine for the railroad whether it “shuts down”. This is most often account the effects of cold temperatures on equipment and track, slowing operations. I have not experienced a situation of excessive heat to the extent that operations were curtailed although I suppose it might happen if the rail “runs” in numerous places. I don’t recall any of the railroads for whom I worked ceasing operations. Traffic was such that the essence of operation was to keep volume moving, weather notwithstanding. Severe thunderstorm and tornado warnings now require certain operations to cease or proceed with caution when such activity is in the area.
The common tactic to fight high ambient temperatures is the ‘Heat Order’, the heat order reduces train speed over the territories where it is implemented by a specified amount of MPH below the normally authorized speed during a specific period of the day. On CSX when I was working when Heat Orders were issued they were in effect between 1300 and 1900. On CSX, at the time, the MofW Officials were the ones that had Transportation issue and/or remove the Heat Orders.
heat orders at ambient temperatures are one thing However how often have you left some metal tool ( usually steel ) out in the open sun and had it become too hot to handle ? That may be the reason CSX and probably other RRs have the order start at 1300 as the rails continue to heat above ambient temps ?
I recall reading sometime in the past that some RR ( European ? ) had tried to paint rail whit to reflect some sun light.e