Re: Re: Gold Coast tram curve wear
  Richard Youl

The Gold Coast trams weight 60.4 tonnes have 4 bogies, only 3 powered. So your 64 tonne estimate is basically correct. 
An 8 tonne axle load is not particularly heavy, especially when shared over nearly 40 metres, but nevertheless massive steel and concrete reinforcing is under the road tracks but the 7km to Helensvale station is ordinary open ballast. 

On 3 Apr 2024, at 9:02 am, Bob Pearce probert@...> wrote:

@font-face { font-family: Helvetica; }
@font-face { font-family: "Cambria Math"; }
@font-face { font-family: Calibri; }
@font-face { font-family: Aptos; }
p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm; font-size: 12pt; font-family: Aptos, sans-serif; }
a:link, span.MsoHyperlink { color: blue; text-decoration: underline; }
a:visited, span.MsoHyperlinkFollowed { color: purple; text-decoration: underline; }
p.msonormal0, li.msonormal0, div.msonormal0 { margin-right: 0cm; margin-left: 0cm; font-size: 12pt; font-family: Aptos, sans-serif; }
span.EmailStyle20 { font-family: "Times New Roman", serif; color: rgb(51, 51, 255); font-weight: normal; font-style: normal; }
.MsoChpDefault { font-size: 10pt; }
@page WordSection1 { size: 612pt 792pt; margin: 72pt; }
div.WordSection1 { page: WordSection1; }
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?



From:tramsdownunder@... tramsdownunder@...> On Behalf Oftransitconsult@...
Sent: Tuesday, April 2, 2024 8:50 PM
Subject: Re: [TramsDownUnder] Re: Gold Coast tram curve wear


 Should have GONE FOR THE Skoda 15T  From memory they had an axle load less than 10 t. 





----- Original Message -----








Sun, 24 Mar 2024 01:20:42 +1100


Re: [TramsDownUnder] Re: Gold Coast tram curve wear

Gday  Mal,All

Strewth,the W only had 4.5 ton axle load,about 6 ton full load and with
real swiviling trucks
No wonder the rails get chewed,esp on curves,esp with the rigid trucks

Cheers,    Mick

On 23/03/2024 2:14 pm, Mal Rowe wrote:
> On 22/03/2024 16:52, TP wrote:

>> I've no doubt that there are design issues on different models of

>> trams that have a bearing on the problem.



> Axle loads are a key issue.


> In Melbourne, the fixed truck D2s have a maximum axle load of 22.2

> tonne (for the centre truck - 11.1 tonne per axle)


> The Es are longer and heavier but have four swivelling trucks with a

> highest axle load of 17.4 tonne (for an end truck - 8.7 tonne per axle)


> The Cs have a quite high axle load - around 21 tonne per fixed truck -

> fairly evenly spread across the trucks.


> One of the key specs for the E class was for a lower axle load than

> the C and D classes.


> Mal Rowe - getting technical