I do find the whispers about VLo reliability interesting. Cummins (engine manufacturer) advertises them as "the most reliable diesel railcar in the world", which is a pretty serious claim given that DMUs make up a very large percentage of the current rollingstock market. They base this on a Mean Distance Between Failures of 150,000km+, some 50% higher than the design spec. (I wish my car went that long without carking out!)
The significance of this number is borne out by the V/Line annual report, where the 157,805km MDBF of the VLos compares with 162,895km for coaching stock - and 22,957km for locos. In other words, the average VLo is as nearly as reliable as a box on wheels.
Availability statistics tell a similar story. VLos operate at 91.7% availability compared to 74.3% and 70.2% for carriages and locos respectively.
So, if the stories are true, and I have no reason to believe they are not, then it must be costing Bombardier a small fortune to keep their reputation intact.
Surprisingly there has been little discussion about reliability and what may contribute to holding a reliability figure. Also the difference between maintainability cost and reliability cost.
The key aspect of the Velocity reliability is its in built redundancy. Focusing on the usual three car set, it has three engines and it takes a fair amount to kill one and become disabled. The usual traveller would have almost certainly had a trip on a Velocity with a failed prime mover. They get along quite well on two engines with no significant impact on run time on most routes. I might also add they become lovely and quiet, a testament to how noisy they actually are. Even with one engine they will likely limp home.
In terms of the comparison of the velocity reliability performance compared to the locomotive performance as a direct measure of the maintenance success, one must be careful as it is not comparing apples and apples. I understand that service delivery is an important measure but the important aspects to deliver the performance requirements are a bit more complex than that.
Considering the Velocity, to have three engines is fine, but it does cost. The complexity, the duplication (triplication) of systems all costs money in terms of capital and running costs. From an efficiency perspective and a maintainability aspect (cost of maintenance) the reduction of numbers is always attractive - ie what a locomotive is. Of course its a balancing act between the impact of a failure (the total cost of a failure, reputation etc) and the cost of providing the redundancy. As a side issue, if a Sprinter was not required to operate as a single car in normal operation, it would never have had the level of redundancy built into it like they have.
Now to the more sinister side of the discussion, having redundancy is like the forbidden fruit in a maintenance sense (not just in rail, all industries). It can hide poor performance of the maintenance function of the organisation. You will never see an organisation willingly give up redundancy. V/Line is obviously addicted to it, someone else (we are!) is paying, so its no surprise to see what we are seeing.
I am merely highlighting that the drive toward a rail car fleet to bring up reliability is a false economy as a huge generalisation of the total issues, that we (as tax payers) are subsidising. It would be fair to say that the N class platform is pretty bullet proof from a world wide perspective. Maintained properly, one would imagine that there would be no way a multi engine platform could keep up with it from an operational cost perspective. The issue with their performance is almost certainly and organisational issue from what I can gather. The nature of the Velocity platform hides such issues, but it costs more.
The opportunities are there to be smarter with locomotive hauled fleets. Yet observing issues with V/Line across the board, one is left not holding their breath. I don't see anyone on the V/Line board with a background to take on the issues in the face of the political pressure. Bombardier for the time being are a sure thing.