London Overground train order number crunching

TfL have put out a short press release announcing a second expansion of the order for new trains for London Overground, a move mooted a month ago. As expected, the order is for 7 additional 4-car trains.

I'd like to say what the new total is, but the numbers don't add up. Previous indications were that the final fleet would be 54 trains, but the press release mentions the 7 as being in addition to the "44 trains" of the original order. They seem to have forgotten about the 3 extra trains they ordered last July.

The documentation for the North London Line upgrade sums up the delivery schedule thus:

• The original order, which was 24 3-car trains for the North London Line, West London Line and Watford DC Line, plus 20 4-car trains for the East London Line
• Tranche 1: Extending the 24 NLL et al trains to 4 cars.
• Tranche 2: 3 extra trains to cover ELL services from Dalston Junction to Highbury & Islington, and 3 trains for the Stratford to Camden Road shuttle, plus a maintenance spare.

Today's order corresponds to Tranche 2. Again, the 3 trains from last July have disappeared. It might just be that they mentioned in this document due to being specifically for the ELL, and additionally whoever prepared today's press release simply forgot about them, but it's all very strange.

On a related note, I've also just spotted that the draft timetable assumes the new diesel trains on the Gospel Oak to Barking Line will be 3-car, which gives some hope they'll be given third cars within the next few years. 

It also mentions  that six trains from the East London Line fleet will be stabled in Stratford overnight, which would mean some or all of the ELL fleet will be dual voltage, as the ELL is entirely third rail and the route to Stratford is AC overhead only. Previously it was thought the ELL would be built without overhead capabilities.

Going back to today's press release, it  notes that the new trains will have the "look and feel of Tube trains" and there will be "six passenger information displays inside" (per train? per carriage?), as well as previously known information about the carriage connections being walk-through (think bendy bus) and the trains having air conditioning.