Western Railroad Discussion > Alignment control couplers

I came across this previously unheard of item in a copy of "Extra 2200 South".
The article said that BNSF require all locos moving over their rails to have "alignment control couplers".This would seriously affect used loco dealers,as the vast majority of switchers do not have them.Ironically,very few BNSF locos have them either.
Can someone tell me exactly what a Alignment control coupler is .
Any info much appreciated,regards,Daryl Kay.

You may be right that very few BNSF locomotives have alignment control couplers, but I find that hard to believe. I have never run an SD40 that didn't have one. A non-self-aligning coupler moves very freely within its range of motion- you can slide it from right to left with ease, and it stays there. Moving a self-aligning coupler is different- it is designed to lock into the straight ahead position when pressure is applied to it. This keeps engines from jackknifing. This danger is very real when 4 or more engines are coupled together. I know- I jackknifed 4 units making a joint coming back to my train in 1973. The MP had about half of their fleet with non-self-aligning drawbars back then. A real pain in the behind. The newer engines had self-aligning drawbars. I can't answer for yard engines- the only time I had one was when I was transfering it to another yard. I never held yard seniority.

Alignment control couplers keep the drawheads from 'slewing' (mis-matching) during coupling and they help keep the drawheads aligned on line of road. Most railroads require alignment control couplers on engines to prevent slack action from pushing the engines off the rail during stops. Without alignment control, the couplers can get shoved to one side, the engine tries to move in that direction, and you end up with the rail turned over and the engines on the ground. Alignment control couplers keep everything in a straight line and any slack action will just shove the engines forward.

Locomotives without alignment control couplers might instead be equipped with truck bolster stops.

They perform the same function of keeping locomotives in line and preventing them from rolling the rail over in DB, when making reverse moves, or when using the independent brakes.

I don't know if the rules have changed but not too long ago it was OK to ship locomotives without alignment control couplers if rubber snubbers made for this job were inserted to keep the couplers in line.

The above answers are correct. A switcher doesn't have them because of the tight curves they operate on and they make a lot of joints on sharp curves. Try that with a road engine. If switchers are moved on the head end, they have to be equiped with drawbar locks. They have to be the 2nd unit and 4th unit if more than one. They may not be against the train. No more than 2 may be entrained on the head end. If not equiped, etc, back to the rear they go, 5 cars from the end with the dead engine feature cut in. Then it brakes just like a box car.

Nudge

Would box cars be equipped with a said type of drawbar? I recall the newer Amtrak box cars having a very limited side to side motion, perhaps a inch or two in each direction if that and that's it, a real pain in the but to switch on curves.

On the UP, a unit without allignment control drawbars must be placed immediately behind the lead unit in the consist. No more than one can be in a consist.
Generally all road type of units have'em, switch engines and Amtrak units do not.

When I was working at Amtrak I saw a curious type of coupler in use. Now I understand what it was. It was their type of Alignment Control Coupler and was on all the equipment. Amtrak uses a type where each coupler head has a diamond shaped pin on one side and a matching slot on the other. This keeps two locked in couplers lined in a straight line both vertical and horizontal. It is more expensive, but with the cargo they carry, worth the cost.

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Johne252 Wrote:
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> When I was working at Amtrak I saw a curious type
> of coupler in use. Now I understand what it was.
> It was their type of Alignment Control Coupler and
> was on all the equipment. Amtrak uses a type where
> each coupler head has a diamond shaped pin on one
> side and a matching slot on the other.

You're describing a Type H Tightlock coupler.  Alignment Control is a different feature, it limits the side-to-side swing.

I was on an "M" or an "H" train out of the Argentine yard at KC before I retired. We'd looked at the list at the office before we were taxi'd out to the train. I noticed the head "car" was an old EMD switcher going west in our train. I went back and looked at it, wondered if we could handle it in our train. I go out my timetable or special instructions, and finally found a rule prohibiting handling engines without alignment control couplers. I looked at the switcher again, to see what I was looking at for sure, then called the tower. They had a Carman come out to verify. And we ended up setting it out. A few days later, I had it as head car again, but this time it had large steel blocks bolted together, limiting coupler swing on both ends.

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MP555 Wrote:
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> Johne252 Wrote:
> --------------------------------------------------
> -----
> > When I was working at Amtrak I saw a curious
> type
> > of coupler in use. Now I understand what it
> was.
> > It was their type of Alignment Control Coupler
> and
> > was on all the equipment. Amtrak uses a type
> where
> > each coupler head has a diamond shaped pin on
> one
> > side and a matching slot on the other.
>
> You're describing a Type H Tightlock coupler. 
> Alignment Control is a different feature, it
> limits the side-to-side swing.

Correct. Just by looking at the coupler itself, does NOT reflect whether it is equipped for "alignment control", as the actual side-to-side limiting component is inside the draft gear. The rear shank end of an alignment control coupler assembly has two "ears" forged into the rear of the coupler shank, and those "ears" fit into the corresponding hard-rubber alignment control portion of the draft gear assembly, in the rear of the coupler pocket. Switcher locomotives 9and any other units) without alignment control draft gear, were shipped from EMD with coupler stop blocks bolted into the sides of the coupler pocket, and bolster stops bolted in place on the truck frame. Both components were supposed to be removed upon deliver and prior to placing the unit into service.