Hello All,

Was searching the web for photos of the 614 last evening for another reason and noticed an unusual feature on the 614.

https://www.pinterest.jp/pin/485896247276626476/

This photo makes it more pronounced due to the angle of the shot and lighter paint color it has on display at Clifton Forge now.

Notice how thick the counterweight is on the driver of the 3rd axle.....then you realize it fundamentally had the same foundry pattern as the first and fourth axle drivers, they simply added more thickness to account for the weight of three rod ends versus one rod end for the first and fourth.

The 3rd axle counterweight almost seems too thick but the Lima designers were being efficient, it only required a slight pattern change! Very interesting.

When you look at what the T1 Trust had to go through in making the Bokpok foundry patterns for their project.....some cost savings here.

Regards,

Randy

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A sidebar, please.
On a Mason as shown, I'm guessing the driving unit (plus guiding truck) is on a separate frame that can pivot on a center pin like the trailing truck. Or is it rigid as on a conventional locomotive but the trailing truck can move from side to side as well as pivot on a pin? Or is that a Fairlie?

The main frame of the locomotive pivots as does the rear truck. This locomotive was sometimes referred to as a Mason Fairlie because it used the Fairlie patent. Think of the double ended locomotives used on the Ffestiniog Railway in Wales.

A Forney used a fixed frame and swiveling rear truck.

Roger

The O.P. is referring to driver #3 on 614 which is not the main driver. The point is that the counterweight on drivers 1, 3 and 4 all appear to occupy the same area on the driver center but are adjusted by their thickness. I've noticed this on other engines as well but never gave it much thought. It makes sense that the connecting rods on driver #3 would be heavier than #1 or #4 but I'm not sure why the decision to adjust thickness rather than area like on the main driver.

In the pre-computer days it may have been easier to calculate the moment of inertia of each of the four drivers if the location was the same and only the mass changed.

Just a thought.

Because the #2 main driver needs a bigger hub around the crankpin, since those pins are driving four drivers rather than just one, and a much bigger counterweight, since it has to counterbalance not only more rod, but also piston thrust. The #3 driver counterweight only needs to counterbalance some extra rod.

In regards to the counterweight on the third driver as well as the second, they are also counterbalancing three side rods. There are two parallel intermediate side rods between the second and third drivers. With the side rods to the fourth and first drivers mounted on the crankpins between the intermediate rods. That additional weight may account for the thicker counterweight on the third driver compared to the fourth driver. Most roller bearing equipped side rods had the twin intermediate rods I believe the N&W J's were originally built with them, but 611 only has one, now. Correct me if I'm wrong.

And then we have this. Counterweights that were so ineffective that they were probably put on for cosmetic reasons only. Solid steel driver centers, burned out of thick plate.