D-block

[piratepete007]

I am gathering some information about catheads as they were used from the 16C through to the 19C - for posting on MSW - and am stumped over the term 'D-block'. This block was used prior to the external cathead coming into existence. Can somebody explain the specifics of such a block as well as locating a suitable diagram or photo to include with it ? This is not being published elsewhere but I would still like to be able to ask for permission to use such a diagram or photo.

 

Pete

[BANYAN]

Hi Pete, 

 

Marquardt shows one on page 250 of his "18th century rigs and rigging - not sure if this would be the same though.

 

He describes it as "D-blocks were lumps of oak, formed in the shape of the letter D, from 12 to 16 inches long and 8 to 10 inches wide(see figure 184j).  They had a sheave fitted and were bolted to the ship's sides in the channels, to take the lifts etc.  The D-block was English and came into use at the end of the century, mainly in men-of-war."

 

This does not tie in with your period but could they have been similar in concept but positioned at the bow?

 

cheers

 

Pat

 

[Edit - Falconer gives the same description; Goodwin does not mention them at all.]

Edited November 11, 2016 by BANYAN

[Richard Griffith]

Arrrgh Pirate Pete, according to William Falconer:

 

"D blocks are lumps of oak, in the form of the letter D, from 12 to 16 inches long, and eight or ten feet wide, they are bolted to the ship's side in the channels, to receive the lifts, &c."

 

 I tried to locate an image in my books but nope.  Falconer's definition is a start but an image would clarify the function.        Duff

[piratepete007]

Pat - thanks for info re Marquardt and this is another book for me to get. Your words are much appreciated. I may have to draw a symbolic figure but maybe somebody will come up with a drawing ?'

 

Duff - I did try to use Falconer but could not find any reference. Thanks for trying to find an image. ( Yeah, that 'piratepete' was my nickname given to me by my beloved students !)

 

Pete

.

[popeye2sea]

Prior to anchors getting large enough to require a tackle to cat I can easily envision a D-Block placed vertically in the bows giving some clearance for catting the anchor.

 

Regards,

[piratepete007]

Henry - that's exactly what did happen but unfortunately as the anchors became larger, damage to the hull forced the introduction of an external beam - the cathead. What I need is a free-to-use diagram or photo to illustrate this.

 

Pete

[BANYAN]

There is a drawing in Marquardt for the D-Block.  While it is for the lifts etc, reimposing it onto the hull for the anchor would probably work.  It is a simple line drawing which, I am sure if you cite the original there would not be a problem?

 

I know Karl Marquardt quite well and I am happy to ask him for permission to use it on your behalf if you would like?

 

regards

 

Pat

[piratepete007]

Pat - that would be great. Thanks.

 

Pete

[Jaager]

I checked our hermit crab - Mondfeld - and he does not seem to have this.

One of the oldest sources - Furttenbach - has an early anchor and a "D" shaped component,

but the two are not related directly and exactly where the "D" goes is not illustrated.

 

A possible way.   Make a mock up of the bow area of a vessel of the era and use the published

dimensions of a D block to make one and try various locations for it pulling up a model anchor.

Whatever works for you has a good chance of being right - or it may at least stir the pot.

 

You could also see if anyone in the Nautical Archeology department at Texas A&M has any data.

[piratepete007]

Jaager - thanks for the thoughts and especially for the possible reference source. Appreciated.

 

Pete