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History of the coupler
http://www.rypn.org/forums/viewtopic.php?f=1&t=35549
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Author:  J3a-614 [ Wed Sep 11, 2013 11:03 pm ]
Post subject:  Re: History of the coupler

Dennis Storzek wrote:
One thing I've not been able to determine is when they were no longer required to be used. Some of the preserved Soo Line steel cars kept theirs to the end of Soo passenger service in 1967, but then again, some of the Soo coaches still had Sharon couplers that late. I've just never been able to determine if they were still connecting the chains.


I can't give a definite date, such as an I.C.C. rule change, but my impression is that the use of chains fell away with the introduction of tightlock couplers. This would be in the streamliner age.

I seem to recall that the Daylight GS-4s had both tightlocks and chains on their tenders, no doubt to cover whatever they were coupled to; I wonder if 4449 still has its chains today.

Author:  Ron Travis [ Wed Sep 11, 2013 11:15 pm ]
Post subject:  Re: History of the coupler

Are safety chains used between steam locomotives and their tenders?

Author:  J3a-614 [ Wed Sep 11, 2013 11:34 pm ]
Post subject:  Re: History of the coupler

Ron Travis wrote:
Are safety chains used between steam locomotives and their tenders?


They used to be, but the stress between a locomotive and its tender grew even more rapidly than that in the cars behind it, so those went away somewhat earlier, replaced by double drawbars.

In some cases, the "chains" were actually a pair of long bars, one on each side of the main drawbar. These safety bars had a round eye at one end, and an elongated slot at the other; this was to allow for the change in distance between connecting points as the locomotive and tender went around curves. Like chains, they would break when needed most, and this eventually lead to the double drawbar, along with the other things like the massive spring buffers that came into use to minimize slack action between a locomotive and the tender.

The use of a buffer between locomotive and tender wasn't something to be discounted. The spring loading, or tight clearances in the case of unsprung or rigid buffers, contributed to better tracking of the locomotive and tender, making them behave almost like an articulated pair as they ran along the track and around curves. One of the benefits was better riding in the cab; an engine with drawbars loose and a buffer that was out of tolerance (both due to wear) could have a horrible ride, largely because of the slack action between locomotive and tender which resulted in the tender bumping and jerking the locomotive with almost every turn of the driving wheels, due to the pulsing pull that a steam engine has.

As usual, John White covered both safety chains and safety bars in his book on 19th century steam locomotives.

Author:  Ron Travis [ Wed Sep 11, 2013 11:49 pm ]
Post subject:  Re: History of the coupler

Thanks for that information J3a-614. I will have to check White's book. Safety chains between engines and their tenders are something that never really occurred to me before. But I do have two coupling links that I dug up that I assume are links to couple tenders to their engine. Both are broken from parting. I wondered about the day that happened. And I wondered how common it was for crew members to get killed when engines separated from their tenders. I don't recall ever hearing of that kind of accident.

Author:  J3a-614 [ Thu Sep 12, 2013 12:02 am ]
Post subject:  Re: History of the coupler

Ron Travis wrote:
I don't recall ever hearing of that kind of accident.


Interestingly, such an incident occurred relatively recently, in the preservation era. The locomotive involved was the 4449--yes, the Daylight--and if I'm recalling the description of what happened correctly, the cause was some small part working loose that allowed the drawbar pin to fall out of its pocket on the tender. Of course, with double drawbars, the same pin holds both in, and the engine separated from its tender. Automatic valves closed the oil and water lines, and the locomotive and tender are connected with glad hands for the air system like a pair of cars, so the two stopped apart. The crew sent someone hiking back, and they found the pin in the center of the track. It was hauled back, replaced in its pocket, everything hooked up, and away they went with minimal delay.

I believe this occurred on the World's Fair Daylight operation around 1985 or so. Afterwards, everyone thought they'd dodged at least a couple of bullets that day. One was that this had occurred either before or after crossing a high bridge over a lake; losing the pin while on the bridge would have made location and recovery an interesting job. Equally of note is that the pin didn't wind up going under a wheel and possibly causing a derailment. Later, the Daylight crew would install a plate that was welded over the location of the pin from underneath. It may require cutting the plate whenever the engine is in overhaul, but that's not something done too often, and it's considered good insurance. If it happened once, it could happen again. . .

EDIT: I haven't checked my copy of White's book, but I seem to recall him mentioning this happened on several occasions with Winans camel locomotives. Those early coal burners had a firebox that was cantilevered from the boiler barrel, the frame ending just forward of that point. This was to gain some extra width for the grate. Of necessity, the long drawbar had to run from the rear of the locomotive frame under the grates to the tender. You can imagine the softening effect of a hot fire, combined with a hard pull. And remember, these locomotives were the coal-dragging 2-10-2s of the 19th century. . .

Author:  Ron Travis [ Thu Sep 12, 2013 9:30 am ]
Post subject:  Re: History of the coupler

J3a-614 wrote:
Ron Travis wrote:
I don't recall ever hearing of that kind of accident.


Interestingly, such an incident occurred relatively recently, in the preservation era. The locomotive involved was the 4449. . .


Actually, now that you mention it, I do remember reading about that incident. I suspect it did happen frequently in the early era where more things went wrong in general. I have speculated on the origin of the two drawbar fragments that I have found. Circumstances lead me to conclude that they failed pre-1900. Drawbars are hidden when in place, so I have no idea what they would look like without seeing drawings. I suppose one clue would be pin diameter. In the case of the fragments that I found, one has a hole for a 2" dia. pin, and the other has a hole for a 1-1/2" dia. pin.

Since pin diameter evolved upward with locomotive development, and reached 3-4 inches, I suspect that 1-1/2" dia. is quite early.

Author:  F.N.Kuenzel [ Thu Sep 12, 2013 9:58 am ]
Post subject:  Re: History of the coupler

Ron, You mentioned digging up 2 broken coupling links used for coupling tenders to engines. Are these different than the coupling links used for RR cars from that era? Are they larger,longer ect?

Author:  HudsonL [ Thu Sep 12, 2013 10:19 am ]
Post subject:  Re: History of the coupler

The "Business End" of a modern Northern Pacific Ry. Tender
circa early 1950s. In this case NP 2659 a A-2 class 4-8-4.

-Hudson

Correction: It appears this is the locomotive end.

Attachments:
Stvenson_WJ_23-010.jpg
Stvenson_WJ_23-010.jpg [ 105.08 KiB | Viewed 1976 times ]

Author:  joe6167 [ Thu Sep 12, 2013 1:15 pm ]
Post subject:  Re: History of the coupler

Drawbars and safety bars:

http://www.trainweb.org/j.dimech/6167/drawbar.html

Splitting CNR 6213 (including stoker conveyor)

http://www.trainweb.org/j.dimech/6167/6213-4.html

Barco Flexible Joints

http://www.trainweb.org/j.dimech/6167/bfj.html

Franklin Radial Buffer

http://www.trainweb.org/j.dimech/6167/e1rb.html

Author:  Ron Travis [ Thu Sep 12, 2013 4:53 pm ]
Post subject:  Re: History of the coupler

F.N.Kuenzel wrote:
Ron, You mentioned digging up 2 broken coupling links used for coupling tenders to engines. Are these different than the coupling links used for RR cars from that era? Are they larger,longer ect?


They are not like car coupling links. They are heavier and more complex in shape. The one with a 1.5" dia pin hole appears to be forged wrought iron. The one with a 2" dia pin hole appears to be cast iron. They are shapes with various rib features, and raised material around the pin holes.

The one with the 2" pin hole is broken off through the hole, and it is the short end of that break. I assume it was a basic bar shape with two pin holes. The bar cross section is 2" X 10".

The one with the 1.5" pin hole has a more complex form. This one too is apparently the smallest portion of the broken whole link. There are tapers, and varying thickness. I made a drawing of it, and then extrapolated what the whole piece looked like. Actually, it does not have a hole of 1.5" dia, but rather a slot with a 1.5" round end. So the whole link would have had a full slot with each pin at each end of the slot. In that sense, it would be like a car coupling link.

I mentioned this link a while back in relation to a question as to the origin of arc welding in railroad practice. This link is so hard that it rings like bell when you tap it. It is a very high pitched zinging sound.

Author:  JimBoylan [ Fri Sep 13, 2013 2:11 pm ]
Post subject:  Re: History of the coupler

The Reading Company non streamlined coaches that New Hope & Ivyland RR got in the mid 1960s still had chains, some broken. The Reading MU trailers that had been made from similar coaches had the sockets but no chains in 1976. I don't know what was on the MU cars built new about 1949, but they were the ones with only 1 cab, if you see any unscrapped today. I don't remember what the Reading streamlined coaches had, but the remains of 3 are still on NH&I today, also some Jersey Central coaches there and on Black River & Western across the river. Can someone please look?

Author:  Ron Travis [ Fri Sep 13, 2013 2:29 pm ]
Post subject:  Re: History of the coupler

Thanks HudsonL and joe6167 for posting photos of engine-tender drawbar details. Do the double drawbars share the load, or does one take over if the other one breaks?

Author:  joe6167 [ Fri Sep 13, 2013 3:23 pm ]
Post subject:  Re: History of the coupler

From my article:

Quote:
"The Safety Bar is longer then the Drawbar and ordinarily does not take any of the pulling force that the Drawbar handles, unless the Drawbar breaks. The top bar is the drawbar, while the bottom bar is the safety bar"


I couldn't remember off the top of my head and had to look it up! Good thing I wrote these articles, it saves me having to remember all this stuff!

Author:  Ron Travis [ Fri Sep 13, 2013 6:03 pm ]
Post subject:  Re: History of the coupler

Joe,

I can imagine that the safety chains would just be a backup in case a drawbar breaks, but what about the double drawbars? Are they sharing the load or is only one under load, and the other there to take over in case the one carrying the load breaks?

Author:  joe6167 [ Fri Sep 13, 2013 6:52 pm ]
Post subject:  Re: History of the coupler

Quote:
"The Safety Bar is longer then the Drawbar and ordinarily does not take any of the pulling force that the Drawbar handles, unless the Drawbar breaks. The top bar is the drawbar, while the bottom bar is the safety bar"

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