I'd put money on 317's being the only EMU's in the franchise to be replaced, they are the worst performing Electric fleet in the area.
I'd bet the whole fleet will be replaced - Roger Ford was highlighting this month that new rolling stock is becoming a lot cheaper
"New challenges for rolling stock market As I explain on the column, the modern perception is that the Rolling Stock Companies (ROSCO) were sold off for a pittance and turned out to be risk-free money machines. Well, I was there at the time and only four serious bids were received, three of them from Management Buyouts. In the case of the consortium I was advising, the high street bank providing the finance pulled out two days before bids were due to go in because the Chairman through the deal too risky.
Since then, with continuous ridership growth outstripping capacity, pretty well everything on wheels has been in demand. As the Table in the April Informed Sources showed, between now and the end of the current Control Period 5 in March 2019, some 4,000 new passenger vehicles are due to be delivered. While 60% of these are state procured and funded the Intercity Express Programme (IEP), Thameslink and Crossrail fleets - 1500 are being privately funded, around 1000 of these by the ROSCOs.
Meanwhile, new train prices are falling, thanks to a combination of large production runs and operators going for lower specifications. Even better, the cost of funding for new trains has been slashed.
So cheaper trains costing less to lease; whats not to like? As ever, the rolling stock market is not as straightforward as it seems.
First of all, there is the 1 January 2020 deadline for all rolling stock to be compliant with the accessibility regulations derived from the Passengers with Reduced Mobility Technical Specification for Interoperability (PRM-TSI). That is just over 1300 days away
Already ex British Rail multiple units are being made PRM-TSI compliant during C6 heavy overhauls. But that expenditure is taking the risk that operators will want to keep these trains in service after 2020.
To mitigate this risk, the ROSCOs are choosing to double up the bet by investing in upgrades to make the trains even more attractive to both passengers and operators. Thus Eversholt has begun upgrading the Greater Anglia Class 321 fleet under the Renatus programme, with retractioning with three phase drives an option. Similarly with Porterbrooks retractioning of South West Trains refurbished Class 455 fleet.
Sounds reasonable until to you combine more-affordable new trains with DfTs weighting for quality in franchise bid evaluation. As Transport Minister Claire Perry said in a written answer on 10 May, the specification for the replacement Anglia franchise requires bidders to include high quality rolling stock in their offers. She added that 30% of the available quality points from the franchise evaluation will be awarded for rolling stock improvement plans, the highest level in any franchise.
With cheap new trains at rock bottom lease rentals it seems certain that replacing Anglias Class 317s, and perhaps the Class 321 fleet, could be a winning move. And why stop at the ex-BR EMUs? The Class 360s are getting on too. "
Roger Ford informed sources