I was just wondering if anyone has developed any clever ways for getting wrist pins into place on the crossheads of their steam locomotives.

We tried to install one back onto our engine yesterday but discovered that we will have to move the locomotive slightly as there was insufficient clearance between the wheel and crosshead to fit the wrist pin into the crosshead.

While we wait to coordinate the move and the presence of better weather, it dawned on me to ask if there was any better method of getting the sucker into place than two guys trying to haphazardly manhandle it into place, as on our engine it does weigh quite a bit and it is in a confined space, (and one of my fingers did get a bit of a pinch already, and don't want to push my luck).



As an aside, you would think that there would be one single position of the wheels that would allow you to access all of the various pins etc. on the rods. We spotted the locomotive so that the crankpins on that side were exactly in the 6 o'clock position, and that worked just fine for getting the siderods off (the mainrods had been taken off several years ago), but in that position we couldn't get the the wrist pin back in.

Or is having to spot the locomotive multiple times just an inherent part of the process. It must have been fun (and rather time consuming) having to move each locomotive around in a back shop situation, back in the day.

Unless somebody surprises me, you have to position the engine where there is room to back the wristpin into a space between spokes, or in the case of Scullin or Boxpok into one of the holes far enough to get it into the crosshead.

We suspect our wrist pin may even be too large to fit in one of the holes in the boxpok wheel, so just to be safe, and since we are moving the locomotive anyways, we will move her back, so that the small end is over the space between the #1 driving wheel and the back wheel of the trailing truck [EDIT: I meant to say lead truck!], which will then give us ample clearance for the wrist pin.

With the crank pins at exactly 6 o'clock, the nearest (large) opening in the wheels is about 5 or so degrees above where we need it. Looking at my drawings for the Boxpok wheels, I see that the spacing for the holes is at 27 degree intervals starting from the hole opposite the crank pin, and the larger end of the oval opening is 7" in diameter. I'll have to measure the wrist pin next time I'm down there.

Of course, to further add to the mystery, I did some sleuthing and sure enough, when we removed the wrist pin 6 years ago, the locomotive was in exactly the same orientation as it is this very moment and somehow they (I wasn't there that day) were able to get it out.

I might have thought you would install it first, leaving the bearings off the main driver, there may be just enough slop to let the main driver move left right, install the crosshead, hang the driver end on the main driver pin, use jacks to turn the driver to position, put the bearings in and yer in.

This design uses floating bushings on all (but the first) crank pins. All the side rods are on, everything else is on, getting the wrist pin in is the last step in getting the rods back on.

The problem is the wrist pin appears to not fit in the space between the wheel and the cross head. The wrist pin measured about 16" long, while there is only a space of about 11".

Further more, we hoped that one of the openings in the boxpok wheels would line up with the small end, giving us extra room to get the wrist pin in, but that isn't the case. The locomotive, evidently, needs to be moved, so that the we have enough room to get the wrist pin in.

Yes, you will need to align the parts of the wheel that allow for it to have room with the crosshead and main rod to get it in place. You might also want to drop the big end of the main so you can move it independently of the wheels to get the best approach, assuming the big end is built up and it can be done that way. Pretty much whatever gives you more wiggle room is going to help.

[quote="joe6167"]We suspect our wrist pin may even be too large to fit in one of the holes in the boxpok wheel, so just to be safe, and since we are moving the locomotive anyways, we will move her back, so that the small end is over the space between the #1 driving wheel and the back wheel of the trailing truck, which will then give us ample clearance for the wrist pin.

You lost me here. Engines were built so you can remove the wrist pin (I'm assuming you mean the one in the crosshead and not on one of the rods) without dropping drivers or removing bearings. When you figure it out, you'll wonder how you missed it. Post a photo.

You will probably find that one of the holes in the BoxPok driver is just the right size for that.

If you drop the big end of the main, won't you have to knock the wrist pin out so you can drop the crosshead end to get the big end of the main back on the main pin? Or did I read something wrong into this.

do you have to insert this pin from the backside out or from the outside in?
It may mean you need clearance needing to move the engine so its not aligned on a wheel.

Engine inside or out? how much can you move the engine? Or nudge the wheels with jacks.

[quote="Frisco1522If you drop the big end of the main, won't you have to knock the wrist pin out so you can drop the crosshead end to get the big end of the main back on the main pin? Or did I read something wrong into this.[/quote]

If the big end is built up - which means it can be disassembled from the pin, most commonly using a split bearing in a fork and a wedge adjustment. I've never set hands on 6167 so I don't know how it is configured. I do know I've used this to advantage on locomotives that are built this way.

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Thanks Kelly!



Good to know. I was thinking of setting up some cribbing in the space between the wheel and crosshead, in the hopes of making installing the wrist pin a bit safer. [6 Years ago, the boss and I were handling one of the drawbar pins from that locomotive, when it slipped out of my hand... and fell on his finger! Popped the nail right off... The boss almost "got me back" the other day with the wrist pin, when just about the same sort of thing happened, but luckily it didn't get me as bad. Since we have some time until our next attempt, I figured I would would ask here on RYPN, rather than trying to push my luck again!]



Also good to know. I thought maybe we missed something there, and that various back shop foreman were laughing at us from the great beyond!



[Yes, sorry I meant the lead truck!] That is exactly what we ended up doing. We've also supported the main rod with some strapping tied to the valve gear frame in the hopes of providing an additional factor of safety, should something happen to the block of wood.

Maybe I'm dense, but if the pin was removed with the engine parked exactly where she is now, it ought to go back in without a respot... Maybe if you asked somebody who was there when it was removed, he might have some good advice, too.

About 25 years ago, I watched a group of senior machinists install a wrist pin on an NdeM Niagara. Steam had been finished there for about 25 years, but these guys had done this job many times when they were younger. There were 4 or 5 of them standing shoulder to shoulder with their feet carefully placed so as not to get tangled up, and so they were in the clear in case somebody dropped something. The rod was still on at the big end, and it was supported at the small end by a chain hoist hung from one of the running board brackets, with a nylon strap around around the rod. All they had to do was tinker with the chain hoist to move it up or down or make fine adjustments. A couple guys handled the pin, the others wiggled the rod or barred the crosshead until everything lined up. They were done in maybe half an hour.

Of course, your engine might not go together the same way. Even if she does, these things always look easy when somebody else is doing them. Best of luck to you.

Take Care & WORK SAFE

There have been times during 765's original restoration the engine was moved no rods, so alignment slipped, just jacking the wheels put them back.
They might have had reason to move their engine and not think about the pin alignment.
I'm just trying to think of ways to align the wheels without moving the engine, chocking all other wheels, grease the main wheels and jackem. Might be a slow tedious job but it would be in full control.