Metropolitan-Vickers Traction Motors-Australia

[Anonymous]

Recently the Denver Rail Heritage Society had the traction motors rebuilt for its Platte Valley Trolley operation (the car #1977 is a replica built by the Gomaco Trolley Company in Ida Grove, Iowa in 1986). Originally it was thought that the traction motors were General Electric but are actually Metropolitan-Vickers Australia Series 101 A and 101 AN. What is the difference (if any) between the 101 A and the 101 AN?

Dan Carroll, Co-Chairman

Trolley Operations Committee

Denver Rail Heritage Society/Platte Valley Trolley

[M636C]

Recently the Denver Rail Heritage Society had the traction motors rebuilt for its Platte Valley Trolley operation (the car #1977 is a replica built by the Gomaco Trolley Company in Ida Grove, Iowa in 1986). Originally it was thought that the traction motors were General Electric but are actually Metropolitan-Vickers Australia Series 101 A and 101 AN. What is the difference (if any) between the 101 A and the 101 AN?

Dan Carroll, Co-Chairman

Trolley Operations Committee

Denver Rail Heritage Society/Platte Valley Trolley

 Wow,

I never thought I'd see anything like a question like this from the USA!

As I guess you are aware, these motors are from Melbourne and Metropolitan Tramways Board class W2 Tramcars, which were built in Australia generally in the 1920s.

It appears that there was a progressive change in the Metropolitan Vickers motors over time, and on these cars, there was a progression from MV101A to MV101AN to MV 101AR to MV101AX. On the later cars classes W3 and W4 there was also an MV101AZ, but these cars had 33" wheels rather than the 26.5" or 28" wheels of the W2.

I don't have my full data available on these cars, but it is known that during the many overhauls in more than fifty years in service, these motors were interchanged on cars so that the (Melbourne No 1A or 1B) trucks Gomaco purchased may have had any combination of these motors. GE 247 and GE247A motors were also used, and BTH (British Thomson-Houston, a subsidary of GE) BTH 265D and BTH 265P motors also appeared on these cars.

However, the tare weights of the W2 cars are shown as follows:

MV101A motors: 16.7 tons

MV101AN motors: 16.8 tons

MV101AR motors: 16.2 tons

MV101AX motors 16.4 tons

This suggests to me that MV were making progressive changes in the motor design, trying to work in more copper into the armature between the A and AN, and cutting out other material to keep the weight down and maintaining performance.

I'm sorry I can't be more specific, but the fact that all these motors were used interchangeably would suggest that the differences were historical, and improvements may have been incorporated in earlier motors.

I know that some motors in these cars had roller bearing armatures, but as I said, I don't have all my references handy, and I guess you would have noticed something as obvious as that.

M636C