Thickness of mast on 1977 Pearson 10m


Most certainly the answer is yes, or 42. 

You can check the mast thickness at a halyard exist if you want, but it’s not going to get better on its own. Put it on the list of things to do with the mast down and start adding more stuff to the list


12 metre

Super Anarchist
English Bay
It may help to know the spar section used.  But if you knew that - you would probably the wall thickness.

Boats of similar size and displacement are likely to have masts with similar sectional dimensions.

I'm not really familiar with the 10M, but given it's displacement, the mast outer dimensions are likely at least 7" x 5".  

Depending on the level of accuracy you need, such a section would likely have a minimum wall thickness in the neighbourhood of 0.15"

You might want to peruse the Rig-Rite web-site:

They have many different sections and dimensions and often have a short sample list of boats that section was used on.

They also have a section about Pearson Spars, which indicates Pearson tended to use Kenyon or Metalmast back in the 70's.

It indicates the Metalmast 7348 section was used on the not too dissimilar Pearson 323 of the same era.  Unfortunately, while it provides the external dimensions (7.3" x 4.8") it does not appear to provide the wall thickness.  The Metalmast sections also have variable wall thickness to increase longitudinal and lateral stiffness.