A type of floor block or tension block.
http://www.ia470.com/primer/flies.htm
From Grand Stage Company - Glossary :
http://www.ia470.com/primer/flies.htm
From Grand Stage Company - Glossary :
Possible origin of the term, from posts to the SML:Tension Block
(Welsh block, floor block) The bottom pulley which turns the hand line from the rope lock back up to the head block.
"Floating floor block in a manual counterweight system. Not sure
origin, perhaps person who developed it at JR Clancy? Or perhaps
someone was pulling my leg."
Bob Theis, former owner and CEO of J R Clancy, told me it was a Clancy
product developed by a Jerry Welsh. Bob has a dry sense of humor at
times and I can't be sure he was serious or not. I'm from the
Syracuse area and Clancy is in Syracuse and there was a popular SU
basketball coach by the name Jerry Welsh.
Dave's answer caused me to do a little research and I found:
http://www.jrclancy.com/Downloads/JRC Rigging History.pdf ,
which has both "Welsh Model blocks" and a J.H. Welsh associated with a
motorized curtain system in 1924. Searching for J H Welsh, I find
someone of the same name stage managing a show:
http://www.ibdb.com/production.php?id=11966 ,
but that is about it.
So I think it is the name for the original floor block that floated in
the T-bar guides and may have been inspired by someone named Welsh,
but in any case was a Clancy product of some sort.
It is my understanding, and I may well be incorrect, that the name
"Welsh block" or "Welch block" is applied to the type of floating
tension block where the sheave is mounted in a cast iron frame, rather
than the type with the sheave mounted between cut steel plate
cheekplates, as a more modern tension block is. But again, that's just
my understanding, and it may well be wrong.
And just to further muddy the waters, there's a note in the JR Clancy
Catalog (pg. 34, for those playing along) that says "tension floor
blocks" (and here they do not discriminate between cast iron and steel
plate frames) are "(A)lso known as "Welch" tension blocks, after the
J.R. Clancy employee who developed the block in 1925."
