Cant help you with your query but maybe you can help with mine!!
I have recently bought a Callisto 460 (a 435 with anchor platform and pilothouse). The hull was built by Croft Marine and she was fitted out by Premier Yachts. Both companies are out of business and, as I bought through a broker, I cannot trace the original owner. I have some electrical wiring diagrams but nothing which relates to the hull fit out.
The tankage seems quite weird as they appear to be double skinned with the void being filled with (what looks like) new engine oil! As this oil does not seem to go anywhere I am assuming that it is there to provide an anti corrosion barrier for both stainless steel water and fuel tanks.
Do you have this system on your boat or can you throw any light on the problem?
Would this be the 1990 435 Distant Drum or the (name unknown) 1998 460 last seen at a Mallorca broker? Have a partial list of Callistos from my own efforts to find out more about the construction and performance modifications.
Assume you are talking about the in-keel tankage? Safran has a 50gal in-keel diesel tank but the 2 x 65gal SS water tanks are separate, resting port and starboard above the keel below the pilot house sole. There is also a 30gal mild steel diesel day tank below the pilothouse sole forward of the engine. The keel was mild steel ribbed and skinned, ballasted with steel and then had old engine oil poured in for corrosion protection. There should be a cap somewhere on the inside where the oil was poured in. The in-keel diesel tank is also mild steel, let into the keel, hence has oil around it between it and the keel skin. The SS water tanks and the day tank are single skin.
You might be able to get more information from www.siriusyachts.com up on the Severn - they took over the completion of several Callistos after Croft went under and took over some of the workmen. Even though they did not finish your Callisto they may know general construction details of the 435. They do have some Callisto files and drawings, was able to get some info on Safran from them.
Hope this is of help. Would be interested in anything you come across on Callsito performance and modifications.
