ADvErT
all yoU EvEr wISHEd To kNow aboUT rIvETS aNd rIvETING!
Mr James Wells, has provided the following information about rivets and riveting
• In the late 1950s Lloyd’s still used to allow “up to 10% of the frames below the waterline to be riveted”. Welding still wasn’t
entirely trusted and some shipping companies still insisted on the 10% rivets below the waterline.
• Rivet quality steel was worked at bright red to faint yellow with Wrought Iron (WI) heated and worked at white heat. This meant
that the latter could travel longer thrown distances without becoming too cold to close.
• Although the traditional method of heating rivets was the blacksmiths style forge there was an electrical method based on a
welding plant system. This certainly produced less slag on the heated rivet.
• The rivets having been inserted and closed while hot would certainly pull the plates together as they cooled but the seams
were rarely watertight. After riveting, the seams would be finally closed by the caulker, which I always thought the hardest
and most soul destroying job of all.
• There was also a very large hydraulic apparatus called “Iron man” that resembled a giant “G” clamp and was used to close
larger rivets but due to the large size could only be used where the rivet seam was reasonably accessible. I cannot now recall
whether this was cold or hot riveting but in the more inaccessible areas, hand riveting reigned supreme.
• The various records frequently mention the reluctance of the British shipyard workers to use more mechanised means of
riveting, such as pneumatic riveting hammers. What seems to be almost completely unknown is that regular use of such
pneumatic tools leads to a permanent deadening of feeling in the hands and forearms.
• Until the development of more modern methods it was also usual for the insurance Inspection team to drill a hole in a selected
hull plate to check for wastage, the hole was then filled by riveting.
• Riveting hammers being in short supply, I had to make both mine in the forging shop. I still possess both and my issue riveting
tongs. Even the riveting hammer itself had a status of its own by being completely differently shaped from that of the Shipwright.
A tea break group of riveters would place their hammers prominently in view as a “riveters only” area and shipwrights did the
same.
• Wrought iron was supplied in two main grades, these being “best treble” and “best treble-treble”. The best treble-treble, used
for rivets, was folded and forge welded some six times to almost pure iron with less than 10% slag inclusion. The slag inclusion,
similar to wood grain ran only down the length of a WI bar or rod, so the bar was far stronger across the “grain” making it very
suitable for rivets. The long slag inclusions were known as “rokes”.
• WI rivets were more malleable than steel rivets and in the event of collision were likely to ‘give’ more than the stronger steel
rivets which tended to shear in similar circumstances. The ability to be heated and worked at higher temperatures was also
an advantage over steel rivets.
• When riveting hull plates in place, the hot rivet would be inserted in the relevant hole from inside the hull by the riveters mate,
held in place by the “Holder On” with aid of a heavy hammer and closed from the outside by the riveter. I am firmly of the
opinion that it is impossible for anybody to be riveted inside a compartment despite regular stories to this affect.
• A TV report about the rivets in the plates from the “Titanic” made considerable mention of the slag inclusion in these rivets. As
WI is very much an unknown quantity in modern times being long out of production, this could cause the wrong conclusion
to be drawn.
• If the rivets examined were indeed traditional shipyard, malleable WI rivets, of the type widely used before WW1, perhaps this
simple fact may have helped the “Titanic” to stay afloat longer than it may have done with steel rivets.
Rina affairs January/February 2010 9
RA Jan 10.indd 9 22/02/2010 15:57:20
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