Hi Bob,

The figures I quoted are from official Yarra Trams documents.

The total weight includes a full load of passengers - not a tare weight.

For the worst offender (the 5 section Combino):

* Total loaded weight is 54,550 kg including 17,080 kg of passengers.
* Bogie 1 has 15114, centre bogie has 22208 and bogie 3 has 17228. 
That's a very unevenly distributed load!

By comparison, the fully loaded weight of an E class is 66,635 kg spread over 4 bogies and the heaviest bogie loading is 17425kg.

Mal Rowe - who prefers an E.

On 03/04/2024 10:02, Bob Pearce wrote:
>

> Umm, I thought axle load was the total weight of the vehicle divided by the number of axles i.e. an axle load of (say) 6 tonnes = a total vehicle load for a 4 axle tram of 24 tonnes.

>

> Not sure, but haven’t the fixed wheel trams got 6 axles?

>

> If so, a vehicle with an axle load of 11.1 tonnes would equate to a total of some 66 tonnes. Seems a tad heavy to me. If they are that heavy, then surely massive road and formation construction would have had to be undertaken to support such weight – especially moving weight.

>

> In any case, if the axle load for a particular truck was calculated to be one figure, and the axle load for another truck was calculated to be another figure, then the total weight is divided by the number of axles to give the (average) axle load.

>

> On that basis, the axle load of 8 tonnes for a tram of 8 axles would be 64 tonnes.

>

> Surely one doesn’t work out the individual axle loads for the number of trucks and add the sub-totals to get the total axle load for the vehicle? And where did the figure of 22.2 tonnes for the centre bogie come from?

>

> If that is what each bogie weighs, that is a heavy piece of gear right there.

>

> What is the axle load for the two end bogies?

>

> Are my prognostications correct, or am I off centre with my data and conclusions?

>

>