Aluminium Mastprofil

Which mast is it?

A customer wants a jockey pole for his S 30 cruising square metre boat  for spinnaker sailing. And matching eye plates to hang in the jockey pole on the side of the mast. That is no big deal. Boom and fittings are enquired at the leading swedish mast builder Seldén via its Hamburg dealer Herman Gotthardt. Seldén supplied the rigging for the S 30 in the seventies. “Based on our documents, it appears that two mast profiles were used. E 170/115 and D 137/113”, says the manufacturer. The order number of the eye plate that allegedly matches both profiles is specified. Seems easy. Order, pick up, pay, stop, drill holes, rivet. Done.

Auszug aus dem Selden Katalog

Obviously this P-profile was not made in 170/110 by Seldén – photo Swedesail

Is it a Seldén Mast at all?

A look at an old Seldén mast brochure in my office shows that it can’t be. Because the S30 has a teardrop-shaped P-profile. An E or D cross-section does not fit what I know of the S30. So I ask the customer to measure his mast and make a template right away. The profile is about 170 mm long and 110 mm wide. Unfortunately, Seldén neyer supplied a 170/110 mm profile. I would like to know for future advice which mast the Fisksaetra manufactured boat has. Is it a Proctor rig? After asking further Swedish contacts, it turns out that it is a spar from a manufacturer called “Gullmars”, which has long since closed down. There are no documents or parts. And now? At worst, we have to buy some stainless steel sheets, have a metal worker bending it, cut it out, drill it, deburr it, weld on the eyes and finally polish everything. Too expensive.

Mastprofil, mit einer Schablone ermittelt

The lateral curve of the existing S30 mast determined with a circle – photo Swedesail

It should by all means be a standard solution. Gotthardt helps with a production drawing of the Seldén mast fitting. I print out the photo of the template in 1:1 scale. The mast has a radius of 139 mm at the side where the eye plates are mounted. Presumably one of the usual Seldén eye plates will fit if mounted at an acceptable slight aft angle. So I order the parts for the customer hoping that they will actually fit as measured at the desk with a circle. The following weekend I receive the above photo from the winter storage. It shows that the fitting fits like a glove on the gold anodised mast from 1978. Even banal things like ordering two eye plates are best done with sufficient time in winter.