Inside Frame Trailing Truck

[Curtis_F]

Michel,

Yes, the first two drawings are from the Baldwin Erecting Cards for Hawaii #5 as you've found a nice drawing of. It is 3' narrow gauge, but the principal is still the same.

As far as I can tell the metal cylinder in the photo is a standard Center Pin rising up out of the top of the Truck Swing Bolster, same as would be found on an Engine Truck. It holds the Truck Swing Bolster on the center line of the locomotive as the wheel sets swing back-n-forth. It should be a slip fit into that upper cross member casting so that it can freely move up and down. There were a few different styles of these and not all Trailing Trucks like this had them.

As to the question on "Center Bearing" on the Engine Truck vs. "Side Bearing" on the Trailing Truck, I can't be certain, but I've done some research. I’m afraid this is one of those things that I’d have to look up specs on several locomotives to find “Center Bearing” and “Side Bearing” specified then go visit each of locomotives to find what’s common with all those of one type vs. the other. There's nothing in the Baldwin Standards Books, which are dated 1938, so those terms may have been passed over by that time. My best guess (shooting from the hip) would be the difference is that the Engine Truck has a single Equalizer arm on "center" whereas the Trailing Truck has an Equalizer on either “side”.

One thing I can tell you for certain is that the same specification is given on the Engine and Trailing Trucks on the Hawaii #5, so it and Skookum have that in common and I would suspect similar design and construction.

The Hawaii #5 Erecting Cards shows a Foot Plate / Drawbar Pocket cross-brace casting with the Center Pin cast integral and hanging down (most apparent in the right-hand side of the end view) which goes down through a hole in the Truck Swing Bolster (best seen in the side elevation view, but hole in bolster can be noted in left-hand side of end view as the center pin is removed from that half of the drawing). That Trailing Truck Swing Bolster is a work of art in and of itself.


Cheers,

Curtis F.

[Bruce_Mowbray]

As Curtis mentioned, the center pin only holds the truck bolster in line with the center of the engine and the pin is free to ride up and down in a sleeve in the locomotive frame. The weight from the equalizer(s) on this type of two wheels truck, be it a lead or trailing truck, is transferred to the bolster, then up through the swing links to the truck frame and finally to the frame mounted journal box springs and finally to the journal box. There are often coil springs tucked in there on this type of inside frame truck to provide some amount of cushion. If you look closely at one of the pictures, you can barely see one of the springs.

[Michel Richard]

Bruce, Curtis.

Got it, thank you.

What it also means is that I should build the front and the trailing trucks at the same time, because a lot of parts will be the same. Look for construction pictures below over the next days / couple of weeks !

Cheers

Michel

[Bruce_Mowbray]

Interested folks,

I have searced all of the places where the drawings for the photographed trailing trucks would hide. No luck. Of course I will keep my eyes open for anything that may turn up while looking ofr OTHER stuff, I will continue to offer any other photographs of details that are necessary to help with your project as well as dimensions and simple drawings/sketches of selected parts.

[hudson]

The Locomotive Dictionary of 1906 contains several drawings for trailing trucks,
see pages 453-455

http://archive.org/details/locomotivedicti00assogoog

Hope this information will be helpful.

Best regards,
hudson

[Michel Richard]

Hudson, thank you for taking the time, but the link does not appear to work.

Michel

[hudson]

New Direct Link:

https://ia700303.us.archive.org/28/item ... sogoog.pdf

Sorry for the inconvenience.

Best regards,
hudson


NB Checked the link, it works for me.

Another way would be to go on the first mentioned link to HTTPS,click on it, then a new page with
a selection of files opens and to choose the pdf one.Normally the pdf link on the first page with
the description of the book should work in the US.

[Michel Richard]

works for me too

See pages 310 and forward (approximately) I did not know those books were online, makes for an interesting read !

Cheers

Michel