Lignum Vitae

As a timber, Lignum Vitae will always remind me of my days at sea.  It was not a timber you actually saw during the normal course of events, but it was integral with the propulsion system, and that it was the material of choice always fascinated me.

The ships in question, at least that I was dealing with were the Leander Class frigates, but many of the same vintage (WWII – 1970s) used Lignum Vitae (LV) in the same role.  It is a very dense timber, so much so that it does not float, (weighing around 1.3 times that of water (less that of sea water!)), and is a very oily timber, so is self lubricating.  Both the density and self-lubricating properties made it ideal for the role, and being an ironwood, is extremely hard-wearing.

On some ships, LV was used in other bearings in the propulsion system, and in the stern tube (which stop water getting into the ship around the ship’s shaft), but not here (as far as I know!).  On the Leander frigate, it is used in the A frame – at the very back of the ship.  The A frame supports the end of the shaft, just near the props.  They remain immersed in sea water, and have to carry and support the weight of the shaft and prop, which is not the nicest of roles for any material, and yet LV got on, and got the job done. Unfortunately, the popularity of the timber for ship propulsion systems, and other large bearings has significantly depleted stock around the world, but hopefully, given other materials have since become more popular, overall demand has decreased and LV trees have a chance to come back.

To give you a sense of scale, here I am in the drydock beneath HMNZS WAIKATO (another Leander frigate – not the one pictured in the first photo – it is hard to get a photo of one’s own ship while at sea!)

So that’s a little story behind the scenes about Lignum Vitae, and why it always has particular meaning to me.  Sadly (and something I do want to recitfy), I’ve never actually owned a piece….yet.

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