What's really gone wrong? - May 2019
With the benefit of his many years’ experience and his acknowledged expertise, on more than one occasion Michael Pye has commented to me that only three things ever go wrong with a construction and engineering project.
In Michael’s view those three elements are design, materials and workmanship. Either the designer has made a miscalculation of whatever nature, or the materials are faulty or the workmanship has been incorrectly undertaken. Although his pronouncement is delivered in a half jocular manner there is, as the saying goes, many a true word spoken in jest.
It is ironic that whilst a good number of disputes depend upon a complex web of facts and circumstances and an even greater complexity of legal principles a large proportion result from quite straight forward mistakes linked to one or more of Michael’s three factors
It’s not just in the construction and engineering field that relatively minor mistakes can lead to things going wrong, sometimes with tragic consequences.
When the submarine Thetis sank just off the coast in 1939 with the loss of almost 100 lives after standing nose down on the bottom with its tail out of the water the subsequent investigation discovered a number of causes, some of which were relatively small in scope but critical in effect.
One error was as simple as too many coats of paint applied to the handle of a bulkhead door so that it could not be closed. Another was enamel allowed to drip and solidify inside the test tap on the seaward side of a torpedo door. As is so often the case, the net effect of several factors together was cataclysmic even though in isolation none would necessarily have led to such a disaster.
In 1957 the Sutton Wick Air Disaster occurred because the feed pipe from the fuel tanks to the engines included a one way non-return valve intended to prevent fuel running back into the tanks and so starving the engines of fuel whilst the aircraft climbed to higher altitude. In fact the valve had been installed the wrong way round so as to cause the very result that it was designed to protect against. Early on in the flight the RAF plane lost power and plummeted down resulting in a crash that caused the then largest number of military casualties since the end of the Second World War.
Fortunately such dreadful outcomes are relatively rare in any area of activity but from my own experience I would suggest there are a number of very common reasons for things going wrong in the construction and engineering field. They are respectively (1) ground conditions, (2) site boundaries, (3) site access and egress, (4) thermal expansion and contraction and (5) the ingress of water.
On many occasions I have come across such challenges which are not necessarily averted by however expert the design, high quality the products or top grade the workmanship.
A recurrent factor of ground conditions is geotechnical investigations and surveys with bore holes undertaken across the site. Despite such precautions the soft spots can be between the lines of the boreholes or they just happen to miss each other. In instances aplenty development land everywhere becomes ever more precious. As prices become more expensive plots of land that were in past times never considered as suitable to be built upon become viewed as attractive new development locations.
Locals – especially the older locals - always express astonishment. What? They are going to build there? On one site on the Fylde Coast 10 metre deep piles were specified for a housing estate on a very sandy location. To avoid subsidence it was necessary to eventually sink piles that were 30 metres deep – and that for a development of single storey dormer bungalows.
Site boundaries present other problems especially where not clearly established by any boundary marker or other fixed points even where plans or maps may seem clear. At one retail centre in County Durham the drainage system was intended to tie the new main drain into a major public sewer running under a highway immediately adjacent to the site.
Except that it didn’t.
The sewer was in fact situated just the other side of the boundary under a strip of land owned by someone else and which was located between the site and that highway. A very difficult, awkward and avaricious someone else. Or maybe someone just taking advantage of a windfall opportunity.
Many a time entry into or exit from a site can present a challenge especially with the very large wagons now upon our roads. Often it’s as simple as the edge of the site not actually abutting the public highway with a small strip of land in other ownership blocking the way.
In city centres narrow side and back streets can be precarious. It can even be that the critical access is blocked by a neighbouring project for which there is a either a road closure order already in place or a festoon of scaffolding across half of the jointly owned alleyway. Or both.
An extremely frequent source of difficulties is thermal expansion and contraction. So many times does one come across this issue. However it generally arises as a result of one or other of the three reasons Michael gives: predominantly design, such as a lack of expansion joints, or quite possibly because of a hands on failure of forgetting to include the insulation.
Otherwise a common cause of things going wrong is ingress of water. Unseasonably high rainfall, high water table, proximity of watercourses, blocked drainage channels. More than a few cellar projects have not been successful because, despite the installation of waterproof tanking, water in the surrounding ground has seeped through via routes that were not readily anticipated.
In addition to all of these scenarios and taking into account Michael’s three factors there is always that other occasional complication. Superbly prepared contract documents. It’s just that someone forgot to get them properly signed up …..