News extras

From January 2009 newsletter

DERRICK DAVISON , 1929-2008
A tribute by Balliol Fowden FYDSA, Anglo European Marine Ltd

Derrick was an inland waterways pioneer in many ways, with a lifetime record of innovation on the inland waterways. He built remarkably long-lived ferro concrete boats in the sixties, which never caught on but many are still around. He also built some of the earlier production GRP inland waterways cruisers (the "Trentcraft" range), many of which can still be spotted in service as far afield as France. Derek was one of the pioneers in production steel narrow boat building (the "Davison Short Boats") and set up one of the first and since most successful inland waterway brokerages ("The Narrowboat Register"). At Sawley, he built one of the largest inland marinas in the UK, again a bold and pioneering act for the time.

His was an act that many have tried to follow, often vainly. In particular he was one of the very first inland waterways surveyors. He was also the instigator of the YDSA Inland Waterways Group, I think our first sub-group, and served as IWG Chair for some fifteen years.

Derrick was a very well respected and admired colleague in the industry. He was always very modest about his achievements and went about his business quietly and professionally. Surveyors as a breed lay themselves open to criticism, but in my near forty years active on the canals I have never heard any criticism of Derrick's work. He had an impeccable record.

Professionally, I will miss his encyclopaedic knowledge of the smaller fibreglass cruisers of the sixties and seventies, which were perhaps his Mastermind speciality. He would always patiently allow me to pick his brain, asking me pertinent questions such as whether it was the model with the large windows or the one with the slightly smaller ones.

Derrick died on October 30 in Derby Infirmary, following a stroke. He will be very sadly missed, both for his professionalism and his knowledge of the subject, but I am sure he has passed on much of this lifetime experience to his son, Ralph, to whom my thoughts go out.

 

NON-METALLIC SEACOCKS – INSPECT YOUR CLAMPING BOLTS!

A non-metallic seacock is an attractive proposition for owners of many types of boat, particularly metal ones, as there is no possibility of galvanic corrosion in an item which is critical to the integrity of the boat. The assembled unit is corrosion-free (on the inside), low friction, and requires no lubrication. It is almost impossible for scale or grit from the seawater to get into the contact area between ball and valve body. With the non-metallic (plastic) material kept in compression by four stainless steel bolts and nuts bolts, the assembled unit is also very strong.

However, the integrity of the assembly obviously depends on the clamping action of the 4 bolts keeping the two halves together. If the bolts become loose the unit will leak and should the bolts fail, the unit will separate with catastrophic results.

In practice, if the unit is mounted in the vertical plane (as is normal), and if seawater leaks or drips from the hose connection, it will accumulate on the horizontal upper flange, which will always be wet. This environment can lead to stress corrosion cracking of the stainless steel in the area between the head of the clamping bolts and the Marlon surface of the flange which is wet, salty and oxygen-free. The result of this corrosion mechanism is for the heads to eventually drop off the bolts, thus destroying the clamping force which keeps the unit together. In the extreme, the two halves of the unit will separate and the valve will fall apart.

In conclusion, non-metallic seacocks are an excellent choice for many boats but the clamping bolts must be maintained in good condition. Clamping bolts should be inspected at least annually. If evidence of corrosion is detected around the bolt heads, those bolts affected should be withdrawn and replaced. Single bolts on any valve may be withdrawn and replaced whilst afloat, if necessary, provided that the remaining 3 are known to be intact and tight. If there is any doubt about the condition of the other bolts, a safer procedure would be to have the vessel hauled out and work carried out ashore.

Information supplied by Richard Ayres, Chairman.

 

UPGRADING MOISTURE METERS

The latest model Sovereign Quantum moisture meters (the yellow box ones) can now be upgraded in two ways. There is a facility available to fit a changeover button to the sensor head that allows one-handed changes from deep mode to shallow mode which is more convenient than using the switch on the meter display panel. This requires an upgrade of the software and so the program chip is changed to the latest version at the same time. There is a change to the scaling on the relative scale to allow the readings to more closely mirror those of the traditional Moisture Master meter (the one in the black case) at the lower end of the scale. This has been done to allow easier comparison between readings from previous surveys and those taken with a Quantum.

The upgrades cost approximately £35 for both and are available direct from Sovereign subcontractor Glasson Electronics, Harbour House, East Quay, Glasson Dock, Lancaster LA2 0BU. Tel 01524 752208. Email: info@glassonelectronics.co.uk. Glasson can achieve a quick turnaround if they are notified in advance to allow them to get the parts ready.

Information supplied by Ian Anderson, AND Marine Ltd.