Weight of Deltic Wheelset

[Stevebr]

AS part of some research into rotating loads and unsprung mass I'm looking for the weight (with or without the gear wheel) of a wheelset (axle + 2 wheels) of a Deltic & Class 47 locomotive.

[Welly]

I would have estimated the weight of each wheel from the wheel thickness, diameter and the density of steel.

Edited March 6, 2021 by Welly

[keefer]

The locomotive diagram book (courtesy the Barrowmore MRG site) has unsprung weights per wheelset.

 

PDF of Loco Diagram Book MT25

 

This has 3t 11c for Class 47 (wheel dia. 3'9") and 3t 6c for the Deltics (dia. 3'7") - these had nose-suspended traction motors so not sure how much that is included in the unsprung mass.

For comparison, the Class 41 Prototype HST Power Car has fully suspended traction motors and unsprung mass of 2.20 Tonnes (dia. 1020mm = 3'4")

Edited March 6, 2021 by keefer

[Stevebr]

Hi,

 

That's great. Not sure how I missed the Barrowmore book.  I've also found GM/RC2513 from RSSB which used a Deltic to to set the standard for all future P2 calculations. (D9001? at Didcot in the early 1970's on dipped rail joint tests if I recall). This give an un-sprung mass of 1680 kg/wheel which is only 60kg/axle higher than MT25.  This seems to equate to an wheelset weight of 1.3 to 1.4 tons including the spur gear. The US SD45-2 has a measured wheelset weight of 1.5 tons.

 

Thanks for the help!

 

 

[Stevebr]

Sorry the SD45 should read 1.7 tons! (axle 1325lb, wheel 1015lb*2 spur 409lb = 3764lb or 1.7t)

[Welly]

I suspect the unsprung weights quoted in the diagrams include the traction motors since looking at the Class 31 diagram the undriven axle is 2 tons unsprung whereas the driven axles are about 4 tons unsprung.

[Stevebr]

Hi,

 

The un-sprung mass will include a portion of the traction motor if axle hung. It seems that this % is between 60% and 80% of the TM weight.