I would be interested to see whether it was a false economy. There are plenty of 10 minute delays on the southern WCML caused by and attributable to the TOC not Network Rail. We all know that a 5L arrival becomes a 10L departure because of a missed slot, and then a 10L departure becomes a 15L arrival because it's stuck behind a stopper. I know London Midland's favoured tactic is to then just cancel intermediate stops (especially Apsley and Kings Langley *growl*) but that still costs money.
I'm not talking about having scores of drivers sitting around in case the signals fall over, but cutting out every last bit of recovery and resilience because it is "unproductive" doesn't seem the best idea either.
If I'd said that I'd be labelled "anti railway"![]()
That's all dependant on what the TOC has classed as late running in terms of penalties and stats. But even internally, train planning come up with a cost effective set of diagrams. If a train breaks down causing delays and knock on issues train planning are not a fault, the depot picks up the delay.