Coal hoppers in unit trains need to be AB-AB-AB-AB and so on for trains where cars are dumped one at a time, and AB-BA-AB-BA-AB-BA-AB-BA etc when the hoppers are dumped two at a time.
Otherwise the rotary coupler won’t work right.
The rotary coupler is on the A end, assuming that the B end has the brake wheel. On hoppers with a rotary coupler, the A end has more decoration for easy recognition.
Very interesting Steve.
Isn’t that why dump hoppers in unit coal trains have a colored side panel on one end.
As I understand it, that is the reason Ric.
Steve is right with one caviat… he is refering to rotary dump unit trains. There are unit coal trains that do not have rotaries. And there are unit coal trains without rotary couplers which are broken up car by car to be rotary dumped anyways. (I have personally seen this happen so it isn’t just rumor)
NS has a fleet of rapid discharge hopper which have a large… paddles for lack of a better term, which when depressed by a stationary trackside object will cause all hopper doors to unlock and drop open.
A&B ends on a singular freight car are used to denote the location of things. The B end is always the end with the hand brake. If a train has a defect (such as a hotbox), the detector identifies it as the X axle in the train. But once the car is setout and tagged with “hotbox on axle #3” the carmen need to know which end is the ed we counted from. This is a standard set by the railroads.
On articulated cars, the platforms are identified as A-C-D-E-B, for continuity with the AB ends on a single car. However, on 3-packs, there is usually only one handbrake, and the brakes on the entire car are usually actuated from only a single control valve. On 5-packs, there is usually a hand brake at both ends (in which case the AB is used primarily for identification purposes) and there is 2 or 3 control valves, depending on car design.
As for terminology, that is highly dependent upon the road you are on. About the only rules which translate from one road to another are “Clear (Signal)”, “Rule G” and “Restricted Speed”.
On my territory (two different divisions of NS) ALL remote control moves are considered shoving moves, even if the engine is on the leading end.
As for HAZMAT placement, there are a ton of placement regulations concerning contents of cars: how far they have to be from engines/cabooses/passenger cars, either endof the train, other HAZMAT, etc. This is standardized across the nation so that trains from one line don’t cross onto another road and have to be switched around, but also because of uniform emergency response needs.
Here is a pic of NS 119030, described as a “Top Gon Rotary Dump Coal Car.” As you can see, there is no colored panel, but the large NS herald is on the A end, and you can clearly see the brake apparatus on the other end. So, at least on NS, the panel is not necessary. OTOH, BNSF uses both the herald and the panel. I guess they subscribe the the belt and suspenders theory.
From RRPicturesArchives http://www.rrpicturearchives.net/showPicture.aspx?id=1536917
Steve, though I see where you are right in that it is described as a rotary hopper, I do not beleive it is equipped with rotary couplers.
While searching the net for a roster of NS hopper classes, I only found that there seems to be a lack of consensus on the issue. There seems to be two uses for the phrase “rotary gon/hopper”. One is that it is in fact equipped with rotary couplers and can be dumped in a special rotary dumper without being uncoupled from the car in front or behind it. A second use of the phrase seems to mean any hopper which is specifically intended to be rotary dumped, but might lack the couplers to be so dumped while remaining consecutively coupled to the cars ahead and behind.
One of the roadforeman at my terminal is from down in NS coal country. Next time I see him I’ll question him directly about these hoppers to verify if there are any that are classified as rotary dump while simultaneously lacking rotary couplers.