Under the Decks of LV50 – October 2017


Fresh water has always been a major concern for seafarers. From the early explorers hopping down the coast of West Africa, looking for a way East, to the Royal Navy steaming around the world, fresh water has limited the amount of time ships can stay at sea. Lightships were no different – they had to stay on station no matter what the weather. They were anchored up and with no motor relied on being resupplied with food and fresh water as and when the weather permitted.

LV50 (RNYC House Yacht Tyne III) was no different. During her service with Trinity House she was in some of the roughest waters off the South coast of England. Resupplying and changing crews must sometimes have been hazardous and at times best delayed. Fresh water transfer must have been tricky, having to keep the two boats on station while the water was pumped across. Therefore fresh water storage capacity was of great operational importance.

In their first look under the decks in May 2016 the Friends of LV50 Research Group identified two sets of tanks, the first underneath the forward part of the lounge and the second, aft, under the bar. The forward tanks were clearly more recent, being of welded steel rather than the riveted plate of the aft ones. Following correspondence with Anthony Lane, author of one of the definitive books on light ships (Guiding Lights, The British Lightvessel from 1732, Tempus Publishing 2001), it was decided to venture under the decks again in October 2017 to better describe and survey these tanks.

The forward tanks were accessed through the trapdoor in the deck of the forepeak, a relatively easy and well-lit passage. The two large welded steel tanks are centrally located and occupy the whole height of the space available. They were photographed and measured. Each tank is 42” wide, 26” high and 54” deep, a rough calculation giving a maximum capacity each of 215 imperial gallons (975 litres) each. Various features were noted, including inspection hatches and a metal pipe extending from the tanks to the stern along the starboard side. The purpose of these tanks is not clear, they are likely to be water tanks but this has not yet been confirmed. When they were installed is also unsure. Ongoing work by the research group indicate that LV50 had major overhauls around 1911 and 1925 which could have been when these forward tanks were fitted.

The stern tanks were less easy to access through a small trapdoor in the floor of the ‘crisp cupboard’ beside the way into the bar. This tortuous access necessitated some gymnastics but was achieved sufficiently well to map out and measure the tanks. Three riveted iron tanks, rusted through in places, were examined. The place of a likely fourth tank being taken by a large modern black plastic tank. The visible tanks are tapered to fit the hull shape and were likely original features, purpose-built for the boat. These tanks appear on the ‘Waymouth’ drawings dating from the time of the boat’s commissioning. Each tank is 51” wide, 47” deep and 27” tapering to 9” high. A rough calculation indicates that each tank could contain up to 195 imperial gallons (885 litres).

In summary, LV50’s original aft freshwater tanks could hold up to 780 gallons (if there was a fourth tank). It is likely that the 7-man crew needed 1-2 gallons a day per person but possibly significantly more; assuming washing etc. was done with sea water. This would have meant that the crew could originally have lasted roughly  50 – 100 days between replenishments. This capacity was later probably augmented by an additional 430 gallons to give a total 1210 gallons. Using the same calculation this could have lasted 85 – 170 days. This is very much a rough calculation, which should be considered a maximum case. Further research needs to be undertaken to refine fresh water needs and how it varied during the 70 years the LV50 was in service. For example, did she carry beer to mix with the water (grog), as was common in the Royal Navy at the time? When was washing in fresh water introduced?

Thanks to the work of Anthony Lane it is clear that Trinity House consistently increased the freshwater capacity of their lightships. LV50 had 800 gallon tank capacity (1879), LV55 had 1000 gallons, LV61 1600 gallons and LV91 (1937) could hold an impressive 5000 gallons. The early 1900s upgrade of freshwater storage capacity to 1210 gallons, in this context, appears logical; the remaining big question is: when was it carried out?

 Article contributed by Paul Gibson, Friends of LV50

Read the survey report

Figures Part 1

Figures Part 2

Figures Part 3