We apologise for the late-running Crossrail service …

Another big infrastructure project, another set of delays. Nobody could have been that shocked by Crossrail’s admission last month that it would not be opening by Christmas and could be up to a year late. And where there are delays there are inevitably cost overruns – about £600m in this case, which the government fessed up to earlier in the summer.

The British public is used to this sort of bad news. Comparisons with the Channel Tunnel are hard to avoid – remember the embarrassment around that highly sensitive project going a year late and an eye-watering 80% over budget?

The odd thing is that until relatively recently Crossrail was being lauded as the UK’s flagship project where all was tickety-boo, everything running on time and on budget. The National Audit Office was satisfied progress was on track back in 2014. Nothing to see here, we were told. So what changed?

The immediate cause of the delay has been testing problems with the signalling software (see our news analysis this week). Linking new underground systems with overground sections is not straightforward and was made more difficult by an explosion at an electricity substation last year. Unfortunate, but not really a construction issue.

It didn’t escape journalists’ notice that the news was slipped out on the last Friday in August in a press release that omitted to mention the word ‘delay’  – referring instead to a ‘revised schedule’

Neither is the contention that political decisions over the rolling stock provider led to unnecessary delays and complications integrating rolling stock with the new railway. But construction is not off the hook. It appears that M&E and fitout work has overrun and is still ongoing, compressing the time available for testing the signalling and ironing out problems.

The word is that incorrect or incomplete designs have meant work that had been installed has had to be ripped out and replaced. Crossrail denies this but certainly the unions believe the detailed planning that enabled the smooth progress of the initial civil engineering stage was somewhat lacking when it came to the subsequent construction phases.

It was ever thus.

Cracks in the good news story were beginning to show last summer, with the first ministerial admission of “cost pressures” and by the end of the year Crossrail chair Terry Morgan was describing the project as “very close on the funding envelope”. The term “funding envelope” is a slippery one. Under the Labour government in 2007 the full funding package was £15.9bn, a figure that got scaled back under the Coalition government to £14.8bn in the name of austerity. Then in July this year Jo Johnson increased the budget by £590m, so it’s now back up to £15.4bn.

But let’s be realistic – is delivering one of the most complex projects ever undertaken in the UK with a year’s delay and cost increase of less than 5% a bad outcome? Probably not. Nor should it be allowed to serve as an excuse for the UK’s inertia when it comes to infrastructure investment. Waiting in the wings are infrastructure projects that look delayed or worse  – HS2, Northern Powerhouse Rail (aka HS3), Crossrail 2, a new fleet of nuclear power plants, Heathrow’s third runway, 5G mobile networks and flood defences.

If Crossrail can be tarred sufficiently as an exemplar of poor management inherent in the way infrastructure jobs are done, then where will we find the impetus to get these projects finished?

The Crossrail story could just be dismissed as a case of bad news management. It didn’t escape journalists’ notice that the news was slipped out on the last Friday in August in a press release that omitted to mention the word “delay” and instead – in a classic bit of PR speak – referred to a “revised schedule”. But aside from the wording, the fact Crossrail has only come clean about the extent of the problems so close to the delivery date looks sloppy. So, a comms cock-up? Definitely. A project disaster?

Well, that’s still to play for but surely unlikely. If there are no further slippages, there’s every possibility that Crossrail can salvage its reputation and we will still be able to look back on the project as a hugely impressive achievement that managed to link up new and old infrastructure. The problem is that so far there is no word on the new opening date and the costs of the delays have not been quantified, with some predicting they could add another £400m to the project costs.

Such an additional hike would no doubt cause more reputational damage, but if total cost overruns remained under the 10% mark, the anger might subside quite quickly once the expected 200 million passengers a year are able to travel on the new Elizabeth line.

It’s perhaps worth comparing this outcome with the painfully slow progress over Heathrow’s third runway. At Crossrail we are talking about delays affecting the final stages of a project; at Heathrow the cost of political procrastination has hit before the £14bn runway has even been allowed to start.

A third runway was recommended back in 2003, but even with recent parliamentary backing the soonest it could be operational is 2026. This scale of delay is what should really concern us; it not only leads to lost efficiency in delivering infrastructure, it also hits the country’s economic productivity and output. Now that is the kind of disruption we really should not accept.

Chloë McCulloch is acting editor of Building magazine