I have been wondering lately how many trams are required to service each route and how many trams are not available for service at any given time. I am guessing this info isn't publicly available.
I started thinking about this because I live on the 86 which still gets a high proportion of B class trams (even the 11 gets some) and checked the depot allocations on Vicsig. I was surprised to see that no E has arrived since January and in the months before then E2s have been allocated 50/50 with Southbank. I was under the impression that the 96 had all of its allocation, or are more services being added to the 96? IIRC the 96 used to be run by the 21 D2s, then the 5 C2s were added (26 trams) and now the D2s have given way to 26 E class. That's 31 trams for what is quite a short route.
At this rate the outstanding orders for E's (I believe the total order is now 80) wont cover the 27 B class trams remaining at Preston (unless they are thinking of doing a 19 and cut the timetable) and I understand there were no new trams in the budget, which was a surprise.