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Food For thought

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Food For thought

#1

Food For thought

Gary B

>Here is a quote from a US Forest Products Lab publication dated 1969...

The most important and exacting use of lignum vitae is for bearings or bushing blocks lining the stern tubes of propeller shafts of steamships and submarines. The blocks are machined to conform to the curvature of the propeller shaft on one end-grain surface, and on the other side to conform to the curvature of the propeller tube. Numerous attempts have been made to substitute other hard, heavy woods for use as underwater bearings but none contain the high guaiac resin content which makes lignum vitae self lubricating and unique for this very exacting utilization

Re: Food For thought

#2

Re: Food For thought

Mike Jurnigan in Suffolk

>The US Navy no longer uses lignum vita for submarine bearings in the stern tubes. They use a type of plastic material. The last time I saw lignum vita used shipboard was for reachrod bearings on a gasoline tanker. These reach rods ran from the topside of the ship to the bottom of the gas tanks. The bearings were the intermediate supports for the reach rods where they went through the tank. They wanted a non sparking bearing. This was in 1979.

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