Jump to content

Mysterious markings on old Liverpool dock gates


jenevers

Featured Posts

Several years ago I looked at some of the old, massive, wooden lock gates in the Liverpool dock system.

i don’t know why, but the timbers are completely covered in tiny, man made indentations in the surface, maybe 100 per square inch. It’s like someone had to cover the surface by hammering a finely toothed chisel all over. I can visualize some guy tapping a chisel, maybe 5 times a second as he slowly moved it from right to left.

Anyone know why this was done?

Link to comment
Share on other sites

2 hours ago, jenevers said:

Several years ago I looked at some of the old, massive, wooden lock gates in the Liverpool dock system.

i don’t know why, but the timbers are completely covered in tiny, man made indentations in the surface, maybe 100 per square inch. It’s like someone had to cover the surface by hammering a finely toothed chisel all over. I can visualize some guy tapping a chisel, maybe 5 times a second as he slowly moved it from right to left.

Anyone know why this was done?

What about adze marks. Adzes were sometimes used to dress timber and can leave marks like the ones you describe.

 

Howard

 

Edited by howardang
Link to comment
Share on other sites

9 hours ago, furnessvale said:

Total guess, but are you sure they are man made and not some limpet type mollusc?

Sounds like an awful lot of work if man made.

George

Definitely man made. Too regular in pattern..

 

9 hours ago, howardang said:

What about adze marks. Adzes were sometimes used to dress timber and can leave marks like the ones you describe.

 

Howard

 

No because these marks have been made at right angles to the surface. 

Link to comment
Share on other sites

45 minutes ago, jenevers said:

Definitely man made. Too regular in pattern..

 

No because these marks have been made at right angles to the surface. 

Maybe using a chisel like the one near the middle of this photo.

https://www.google.fr/search?q=stone+chiseling+tools&rlz=1C9BKJA_enGB690GB690&oq=stone+chise&aqs=chrome.3.69i57j0l3.6381j0j7&hl=en-GB&sourceid=chrome-mobile&ie=UTF-8#imgrc=imTmLyUwoPzohM:

Link to comment
Share on other sites

Marks made by the  powered toothed rollers used to drag the timber through a saw or planer/thicknesser? Those timbers would have needed some mighty machines. I expect machines to have replaced manpower for the heavy duty  work from about 1880?

Link to comment
Share on other sites

12 hours ago, howardang said:

What about adze marks. Adzes were sometimes used to dress timber and can leave marks like the ones you describe.

 

Howard

 

No one using an adze correctly would leave highly visible marks in timber. Properly adzed timber is virtually flat, hardly requiring the use of a plane. What is replicated today on replacement beams and the like are the marks left by axes.

Link to comment
Share on other sites

Some years ago I went on a visit around the BW lock gate workshops at Stanley Ferry. They showed us an experimental softwood lock gate. The entire surface was covered in pin pricks, and we were told all the timbers had been rolled with a spiked roller, to increase the uptake of preservative that the timbers had been soaked in.

Having not come across a softwood gate since, I can only assume the experiment was not a success.

 

Link to comment
Share on other sites

35 minutes ago, David Mack said:

Some years ago I went on a visit around the BW lock gate workshops at Stanley Ferry. They showed us an experimental softwood lock gate. The entire surface was covered in pin pricks, and we were told all the timbers had been rolled with a spiked roller, to increase the uptake of preservative that the timbers had been soaked in.

Having not come across a softwood gate since, I can only assume the experiment was not a success.

 

Hmm. That sounds like what I saw, although the baulks of timber in the old gates would be a hard wood I should imagine, so preservative may not have been required.

Link to comment
Share on other sites

Where the gates in salt or fresh water I have come across wood being used in salt water that had marks as you describe they were soaked in a copper solution to prevent fouling wouldn't be required if the water was fresh

Link to comment
Share on other sites

39 minutes ago, X Alan W said:

Where the gates in salt or fresh water I have come across wood being used in salt water that had marks as you describe they were soaked in a copper solution to prevent fouling wouldn't be required if the water was fresh

A-ha!

I think we may be getting there. The lock gates are on the tidal  Mersey so would be in salt water.

I can see the logic in piercing the surface to increase absorption of chemicals.

This is the kind of knowledge that gets lost over time.

Link to comment
Share on other sites

Copper was used to plate wooden ships when the effects of Teredo Navalis (ship worm) was found to cause such structural damage as to wreck a ship. More prevalent in warmer Seas and Oceans, it has been found in more temperate climes, though the brackish Baltic seems free.

http://poseidonsciences.com/teredo-worm.html

Copper is also used to prevent or delay the growth of mosses on tile rooves.

I think knowledge is gained whenever it is sought for. It gets lost when we do not seek it, or ignore it. The latter appears predominate in the political classes.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.