Anglican churches in England are exempt from normal planning permission, but have to go through an internal system, which is called a "facility". This is actually tougher than planning permission, and has many steps, but part of the system is that for any significant alteration to a church (and that means anything that affects the structure of the church - including drilling holes to secure equipment), you HAVE to have an architect who is both qualified and who has specific expertise in buildings of the age and type to be considered - every diocese has a list of architects. This architect has to be used from the early stages of asking for permission to do work. Further, at a later stage, every body that may have an interest in the proposed alterations must be consulted - including many special interest groups that most people have never heard of. The result is that we involve professionals from an early stage, and projects are subject to external review through all stages. This is, of course, arduous and (on the scale of church finances) costly! However, the result is that when a project goes ahead, it is well specified and carefully costed. I know all about it because I'm going through it for our church!
IoW Council are skilled professionals compared to Dumfries and Galloway Council who, among other things, has a swimming pool and leisure centre for £17m and then spent and other £16m o council money - on top of a £9m settlement from contractors - repairing it. They spend £28m having a new school campus build so badly that it closed after a month and three other schools had to be reopened. The lastest news is that their Direct Labour Organisation won a contract for trunk roads maintenance and managed to lose £3m on it over two years.
My guess - only a guess - is that it's simply too big and that with a fast tide running relatively straight chains can't hold it in place. So if I was reviewing the calculations I'd be looking very closely at the sideways drag ones.
Sounds sensible. It would require a bit of ingenuity in mounting the model, testing tanks being designed for things going forwards, but the Haslar towing tank is 12m across so there really should be room to pull a model across as the carriage goes up and down the tank.
I'm certainly no expert but the fact is that for many years they had a vessel which worked and to which they could look for a model. If they were going to change that, specifically by making it larger, it shouldn't have been massively complicated to calculate the increase in the underwater surface area and the additional force which would be applied to it by a four knot tide. That in turn would impact on the chains and power needed. I'd like to think that if I were an expert such a calculation ought to have been a doddle, otherwise I wouldn't choose to call myself one.
