So what is it all about? The whole London Underground escalator system seems to be suffering progressive and catastrophic failure. Returning to King's Cross on the 05.40 train from Nottingham last week, I was appalled to find access to the Northern Line barred yet again.
Thousands of furious and frustrated passengers were spilling from pavements onto busy roadways in search of buses and taxis.
These problems exist at many other stations, including Charing Cross and Chancery Lane.
Indeed, Knightsbridge is completely closed, but there has been no explanation of the extent of the problem, its likely duration or its cause. Well, let me tell you, there is a real risk of the effective collapse of the entire London Underground system.
Scaremongering? No, not at all: this is a fundamental problem that threatens to rapidly expand to a point where London is paralysed. It arises from a failure in the manufacture of escalator stair treads, which are being checked for hairline fractures to the metal - just as used to be the bane of the airline industry. But, I hear you say, this is not serious: broken escalators do not fall out of the sky like aeroplanes. Maybe not, but an Underground official told me that such metal fatigue has resulted in a tread collapsing on an escalator in America, causing a passenger to fall into the winding gear - with fatal consequences. For this reason, the London system is being checked escalator by escalator and all those found to have flaws in any treads are being shut down completely - they cannot even be used as a staircase.
Notwithstanding the obvious danger (and breach of Building Regulations - which London Underground has traditionally overlooked when allowing passengers to climb or descend lengthy flights of static escalators) there is the extended risk to safety as the exit provisions in stations are now so heavily restricted: remember the King's Cross disaster where death and serious injury were a consequence of inadequate escape provision.
The full extent of London Underground's hairline fracture problems are, as yet, unknown but they appear to relate specifically to new installations by an American company called APV. Escalators manufactured by Otis, the only type still functioning at Liverpool Street, seem to be unaffected.
This issue, which now threatens the safety and effective functioning of our capital city, demonstrates the extraordinary dependence that dense urban form has on public transport infrastructure. But such reliance is essential for low-density suburban planning and excessive use of motor cars is unsustainable - apparently, if the Chinese were to drive cars for as many miles per head of population as the Americans, the world's entire reserves of oil would be consumed within five years. But before that the carbon emissions consequent on such consumption would have rendered the planet uninhabitable for human life.That is the scale of disaster that faces mankind if we do not get a grip on the sustainability issue and that is why the work of the Chartered Institute of Building Service Engineers, which last week accepted an invitation to report to government within six months with recommendations for a more responsible design approach to building, is so important.
That is also why the decision by the RIBA and ARB to introduce sustainability into the criteria against which schools of architecture are assessed has been so enthusiastically welcomed. As Professor Peter Smith said during the RIBA Council debate that preceded the adoption of the new programme: 'If sustainability is not an ethical issue, then I don't know what is!' This is, of course, the most important theme of Goldschmied's presidency and it is deeply gratifying to find that the institutes representing landscape architects and structural and services engineers are pursuing similar agendas.
Hopefully, we can soon persuade the surveyors and valuers who have such a large impact on building design and technology, but who to date have shown so little understanding of the importance or scale of the sustainability problems that we all face, to join with us in this work.