Also many years ago, there was nothing better. This day and time, I would think we would have better man made products than wood.
Potential mallet head material for Mike Hill
- Thread starter Friedrich9
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It's industry specific. The benefit to lignum bearings is they don't need lubrication or maintenance really at all. And they can be used underwater. In bridge design, most sliding surfaces we spec are either dimpled bronze or stainless steel, and the underlying bearing material is usually just the same steel as is used for steel girders (A992 GR50 or more rarely A36). But the steel and bronze wouldn't work well under water for a variety of reasons. Access to maintain bridge bearings usually just requires a ladder, bucket truck, or snooper, and replacing the bearings requires jacking the bridge but doesn't typically require taking the bridge out of service. Replacing a submerged lignum bearing might require draining the water or require expensive equipment to access and move the bearings (i don't know since it's not my industry).
Newer is definitely not always better. There have been enormous advancements in metallurgy and concrete mix materials and design, yet we often find that the older materials outlast the newer. There are other considerations such as installation and the use of less optimal but more sustainable materials, but there's undoubtedly some relationship between the material itself and it's service life.
Lignum vitae was used for the massive ball bearing in submarines because it didn't require lubrication and was extremely hard. Basically,we used it because it was better than man made materials. There are some kinds of aluminium bronze that can get to steel-like hardness but they are expensive and require lubrication.
Basically, man made materials can be either stronger, resist wear better or stay lubricated for long amounts of time but there isn't a material that has the exact balance of lignum vitae.
Basically, man made materials can be either stronger, resist wear better or stay lubricated for long amounts of time but there isn't a material that has the exact balance of lignum vitae.
I was told that they get their LV from shipyards that are shutting down. I'm sure trees from previous centuries were much larger than anything available today or any time post WW2.
Well the Record paper i was talking about was written in 1921, before WWII, and that paper didn't mention any larger sizes either. The report year was 1921, but the data collection almost certainly occurred towards the end of WWI or earlier. Given that lignum has been exploited for hundreds of years, i think any very large trees would have had to have been harvested long before the world wars and very likely ended up in Europe.
They mention using shipyard lignum but also go into detail about importing it as well, so i they must at least use both sources. But in all likelihood the shipyard stock is already gone. It's not like shipyards are just closing left and right these days. Most closed long ago, and the few that might remain aren't numerous enough to be a reliable source of lignum i wouldn't imagine