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Re: WE WILL DELIVER...eventually!
Author: OPRRMS
Date: 06-26-2010 - 10:51
Q Wrote:
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> Pardon my ignorance, but what exactly is an
> "alignment control coupler"? What "alignment" are
> they controlling, and how. Why are they required
> if coupled next to a locomotive?
Locomotives with alignment control couplers have a different coupler shank and built-in bolster blocks than those that don't, thus the drawbar has less of a side-to-side arc and can help minimize the drawbar slewing over when in buff (such as when the train's slack runs in or when the locomotives ahead of it are in dynamic braking) and causing a derailment. Conversely, they can help prevent a derailment when shoving hard through a switch or on tight curves.
Units without this type of coupler have drawbars with more of an arc, helpful when switching on tight curves.
SP/SSW SW1500's in the 2450-2679 were built without alignment control couplers. After a few unfortunate incidents (including a derailment at Redlands when two were being used as helpers), SP started a program to install removeable drawbar blocks in the coupler yokes. A new rule was established that the blocks were to be in place when the unit was used in road serevice and removed when in switching service, and dictated where these units were to be placed be in a locomotive consist. (Before anyone asks, SW1500's 2680-2689 and all the MP 15's were built with alignment control couplers.)
> Or do all freight cars next to locomotives also have them?
No.
-------------------------------------------------------
> Pardon my ignorance, but what exactly is an
> "alignment control coupler"? What "alignment" are
> they controlling, and how. Why are they required
> if coupled next to a locomotive?
Locomotives with alignment control couplers have a different coupler shank and built-in bolster blocks than those that don't, thus the drawbar has less of a side-to-side arc and can help minimize the drawbar slewing over when in buff (such as when the train's slack runs in or when the locomotives ahead of it are in dynamic braking) and causing a derailment. Conversely, they can help prevent a derailment when shoving hard through a switch or on tight curves.
Units without this type of coupler have drawbars with more of an arc, helpful when switching on tight curves.
SP/SSW SW1500's in the 2450-2679 were built without alignment control couplers. After a few unfortunate incidents (including a derailment at Redlands when two were being used as helpers), SP started a program to install removeable drawbar blocks in the coupler yokes. A new rule was established that the blocks were to be in place when the unit was used in road serevice and removed when in switching service, and dictated where these units were to be placed be in a locomotive consist. (Before anyone asks, SW1500's 2680-2689 and all the MP 15's were built with alignment control couplers.)
> Or do all freight cars next to locomotives also have them?
No.
