The Royal Research Ship 'Discovery'. Part 18.

Using Modern Techniques to Control Historical Troubles

Temperature, humidity and ventilation are the keys to the conservation of the inner hull of a historical wooden ship. Get them right and keep them right then condensation is unlikely to become an issue within the hull to harm any untreated or unprotected timbers. It was when looking at the various means of how to control temperature and humidity that I became aware of the mind-set of some companies (not all) who manufacture or supply such units or systems. The mere mention of a Heritage Lottery Fund assisted Project sent the income expectations of some into overdrive. 'Ours is the best system on the market and it will only cost £250,000 (US$390,000) to supply and fit', was the typical response. Get real!! The one thing that many of the suppliers and manufacturers failed to do was, 'get to know the customer'! Had they made the effort they would have learned that I was working on a tight budget and needed original thinking, not salesmen's chatter.

The system I opted for was simple. Portable, thermostat/humidistat fitted, manual control over-ride heaters and de-humidifiers. These would be placed in the different compartments, a heater at one end and a dehumidifier at the other. First however, a safe, tested, electrical supply had to be made available in all the compartments. When the electrical wiring that was already fitted was tested it was found that it too had suffered from the damp conditions on board. There was no other choice but to rewire the whole system, not by any old electrician but by a qualified Marine Electrical Engineer, one that fully understood the conditions that could prevail on board a historical wooden ship. Arbroath is a small fishing port not far from Dundee and has a history of building wooden fishing boats. Sure enough, a well-known and hugely respected Marine Electrical Engineer had his business premises in Arbroath and he and I got down to business.

The bilge pumping arrangements were a mess. Of a total of 16 pump locations throughout the bottom of the ship only two operated, the rest had succumbed to corrosion and lack of care over the years. The priority decision had to be to get the bilge system fixed and in good working order. Why priority? Well, when the dehumidifiers were up and running they would convert the excess moisture in the air back to water that had to have somewhere to go. Each dehumidifier unit would have a drain hose leading into the bilge where the water would collect. This water could not be allowed to accumulate so it had to be pumped out of the bilges by the bilge pumps, therefore the bilge pumps had to work before the dehumidifiers were activated. Now, a crew member could not be expected to run around 24 hours a day operating the bilge pumps to keep the bilges dry, so they had to operate automatically. How better to do that than fit each with a float switch, a device linked to an on/off switch that operated when he float was raised to a predetermined level by the accumulating water, the pump would operate until the water level fell taking the float with it until the mechanism forced it to switch off. The photographs show the new bilge pumps being fitted. Where possible the actual electric pump motor was fitted to the deck immediately above the bilge in order to provide ease of maintenance and protection from damp bilge conditions.

Ok! Now the water levels in the bilges could be controlled and in fitting the new pumps, including rewiring the electrical system, it seemed like job done! Was that it? Not likely!! What the managers of the ship needed was real-time information of the conditions on board in order to keep her in tip top shape. After discussing the matter with a number of companies it came down, yet again, to cost. Large  high-tech companies quoted silly prices. As is often the case, failure to look at what is at the end on ones nose often hides the obvious. A small Dundee company took an interest in what was going on and came up with an affordable and ground-breaking solution. The activity of the bilge pumps could be monitored, recorded and the results made available on computer using internet technology. The same could be done for the temperature and humidity in each compartment of the ship. The equipment was commissioned delivered and fitted. Discovery's Operations Manager then had the ability to read the results on his computer sitting in his office at Discovery Point.

Bilge pump control panel in the process of being installed

Bilge pump monitoring unit installed above panel.

Remote temperature/humidity transmit/receiver

Temperature/humidity transmit/receive mounted below bridge deck

The great advantage of fitting such equipment was, and is, that it provides an early warning of problems and allows Management to act quickly. For example, if a particular bilge pump shows unusual activity that could mean that a leak has developed in that compartment of the ship immediate steps can be taken to deal with the problem. If a compartment shows that the humidity or temperature require to be adjusted then the Manager is able to order the heater of dehumidifier's controls to be adjusted manually to lower or increase the temperature or humidity. The finer details of the equipment may be of interest to some, so anyone who may want to learn more can contact me by email john.watson32@btopenworld.com .

Next. Restoration continues and replacements are necessary.