Is this a boom support and how is it fitted?

[tkay11]

I am thinking about whether I build my model of the cutter Sherbourne with sails or not, and in the process have been considering how the boom might be supported.

 

The following is a section of the plans showing what I reckon to be a support for the boom, and presume in my ignorance that it might only be used when no sails are on.

 

Could someone advise me of the name and function of this piece and how it is attached to the deck, if at all?

 

If, of course, it turns out to be an old TV aerial or washing line support or even the support for a rather large catapult used in the event of the swivel guns failing, or perhaps a perch for the man at the tiller when he wanted to have a better look ahead, then I would be equally happy of the advice.

 

 

Thanks

 

Tony

[wefalck]

I am not that familiar with these cutters, but believe they had ports for sweeps installed, so that they could be rowed in the absence of wind. The sweeps were stored in such crotches.

 

wefalck

[Stockholm tar]

Tony,

 

I would think you are right. This looks to be a form of boom support or crutch, mounted centrally beneath the boom when the vessel is at anchor, to take its weight when the boom topping lift is eased off. It would probably be made of iron.

 

I had thought about this problem when I made mine, and came up with a 'sheerlegs' type of support. Made of wood and hinged, they are designed to be unshipped when underway and stowed:

 

Edited June 13, 2014 by Stockholm tar

[tkay11]

Darn it! I'm cursing myself for not noticing Kester's photo in his own build, and very disappointed that it's not really a catapult. It would have been fun making a working model of a catapult with the ammo -- it certainly would appeal to the grandchildren.

 

But thanks, Kester, for helping out, as usual. It's a nice idea to make it in the form of a cross -- which makes it easy to set up and perfect for taking weight. However, the drawing shows a single pole with a U-shaped hook, so it looks as though there's another way of doing it.

 

Tony

[Stockholm tar]

Tony,

 

Mine came from ones I have seen used on older type wooden boats. I am sure there were different types. If you go with the one in your drawing, it will be interesting to see how it turns out.

[tkay11]

As I'm very lazy when it comes to working things out, I'll wait a while to hear whether any other ideas come up. Perhaps a battery-operated support that rises through a hole in the deck and unfolds the arms as it rises?

 

The truth is at the moment your idea, Kester, is the most pragmatic and based on something that really worked.

 

Tony

[CAd My Fingers]

Tony, initially when I 1st began drafting the S., I also thought this feature was a boom support now I'm maybe/maybe not since gaining a lot more experience in how draughtsmen depicted features.

 

You may not see it clearly in the picture you attached (due to low resolution), but take a look at where this thing attaches--it's to the outside of the ship. The give aways here are its black lines and its black, ovular fastener. If those lines were in red, it would mean that it was attached to the ship's interior side. For attachment to the ship comparisons, I've included a shot of the chainplates. It definitely didn't attach to the deck or etc, as that's where the rudder head passes through (the lower red lines in the 1st attached picture) the deck. Also, there would very likely be another one these attached to the other side of the ship.

 

Its orientation towards us may either be for clarity, so that one can determine its shape, or is how it actually was attached and faced on the ship. This last aspect is rather crucial in helping figure out its function. If the orientation is how these actually were attached, then they cannot be boom supports; if the depiction is for clarity, then its possible. These have about 9" of attachment to the ship and pass through the sheer rails. I am not sure if this arrangement is sufficient for a boom, yet that fastener is huge in comparison to the chainplate fasteners and how it passes through the rail would, I suspect, provide strength and stability. The cross-ship distance between these is about 12', and the space in the crooks is about 8" wide x 6" high (fwd arm); the boom diameter on the draught is listed as 10 & 5/8". I haven't yet research Steel and company on boom tapers....

 

I'll post an update when I have a better idea about what these are.

 

Cheers,

Jay

 

 

Edited June 13, 2014 by JMaitri

[tkay11]

Now this is really getting interesting, Jay. Great insight! Maybe it really is a catapult. No, ok, I won't press for that. How about something that linked to stern davits for that elusive method of carrying the ship's boat? I wouldn't really buy that either, since it or they are in the wrong kind of position. But I'm looking forward to more ideas as you and others get into this.

 

The curly nature of the prongs at their ends seem to be redundant if they were to be a support, and wouldn't be much in keeping with the rest of the ship -- which surely is far from ornate and is instead very functional.

Tony

[Gregor]

Here is my attempt to make a boom rest. There is one to be seen clearly on the Science Museum cutter (here the link, provided by Jay: http://www.modelships.de/Museums_and_replicas/Science_Museum_London/Ship_model_naval_cutter.htm), in Peterssen’s book.

 

 

Gregor

[Stockholm tar]

Jay,

 

Well, you have me confused now! However, at the present moment, I still think it's a boom crutch with the top orientated towards the viewer (as you suggest) for clarity.

 

I can't imagine what else it would be, unless we go back to Welfack's suggestion of a support for the sweeps. If, as you say, this is mounted on the outside of the hull, then there should be another one – most likely further forward on the ship's side, but I don't remember one from the drawings. Is there one? Having sweeps mounted athwartships in this aft position wouldn't seem likely, as they must be about twenty feet long! They would also interfere with the boom – and I would have thought a few other things!

 

Tony, I was going to suggest that the decorative tops actually form a lip, perhaps to be able to tie the boom (or whatever) down if required.

[tkay11]

Thanks, Gregor. Very nice workmanship, and I'd not seen the Science Museum photos. I had seen the one in Peterssen, but I was intrigued by the different position on the Sherbourne plan.

 

Tony

[CAd My Fingers]

While maybe not catapults, Tony perhaps slingshots? lol

 

Seriously, here's what I strongly think about these: There are two of these on the ship, based on the symmetry conventions of draughts, and they are boom supports.

 

I strongly think how this feature faces us is for clarity and yet also tells us that they are positioned relative to the boom's swing from the mast (the lower forward arm relative to the aft higher arm is the draughtsman's convention of telling us this last piece of information). Here's a very rough picture to better capture how I think these features look on the ship.

 

 

There are other conventions on the draught that lend support to what I've said above about how the draughtsman is conveying these support's positions to us. Slightly above the lower lines of the sheer rail, rail below the sheer rail, and wale is a faint line about a 1/2" (scale) above those lower lines. These faint lines are clues that the rails and wale are on a different planes, i.e., that they are thicker (but not by how much) than their surrounding planking. In the attached photo you can see the faint lines on the rails; also notice the shapes of the port and hawse holes--these shapes tell us that bow is markedly curving inward to the stem.

 

 

Mainly, I need to confirm (i.e., the draughtsman's convention) what I think about theses features but I'm very sure that's what we are being told about these: There is one on each side of the ship and they are angled (high arm is outboard and low arm is inboard) relative to the mast and boom swing. Further, I think the dimensions of these are taken off from the higher (outboard) arm: from centerline of the 'U' upwards to the top of the higher (outboard) arm and from centerline to widest point of the higher (outboard) arm.

 

Or, they really are slingshots!

 

Cheers,

Jay

 

PS Several additional posts popped in before I completed my post. Very nice metal work, Gregor! Kester, I think you're right that the lips on these are to hold in place the lashing that would secure the boom into a support.

Edited June 13, 2014 by JMaitri

[jud]

Now why would you want your boom support on the rail while the boom is not in use? Keeping it on C/L keeps the ship and mast balanced with the end of the boom out of harms way from anything that may be alongside. Wouldn't need a heavy crutch as long as it's compressive strength would support the boom and furled sails without distortion. A simple block on deck would suffice to distribute any concentrated forces from the bottom of a small diameter crutch, forces similar to the contact forces per sq. in. at the end of a 98 lb. woman's stiletto heels. Side sway easily controlled by existing rigging. I will need some very good reasoning and engineering justification for an outboard boom crutch.

jud

[Stockholm tar]

Jay,

 

I'm with you now. You're idea of two boom supports, one to larboard the other to starboard, seems a strong possibility. The mainsail could be then lowered and the boom dropped into the most convenient crutch, depending on what tack the vessel had been on. This would also obviate the need, and perhaps difficulty, of centreing the boom.

 

You're observations as to the differing length of the arms also makes sense.

 

Jud, I'm not sure having the boom crutch to one side or the other would make much difference to stability, but from a practical point of view it would make sense.

Edited June 13, 2014 by Stockholm tar

[Gregor]

Just an observation (I hope I haven't missed it before): Alert from 1777 has a symmetrical arrangement at the stern (unexplained in Goodwin's book) that looks like wooden boom supports. After a quick browsing through the NMM collection I got the impression that these were not essential parts, because they are rarely shown on contemporary models.

Gregor

[tkay11]

Thanks, everyone, for the ideas. I've been out all evening, so missed the discussion and glad to get back to it. I like the idea of the boom support to one side.

 

If it is something on the side, and since in such a position it would be rather in the way of the aft swivel gunners, could it be that it was something that slipped in and out of a sheath on the out side of the boat?

 

If so, that would mean:

 

1. that there would only need to be one, which could be transferred from one side to another according to need.

 

2. that it could be stowed very easily indeed, being relatively small, when not needed at all -- and hence would not be something that would be a normal feature of models as only used for particular occasions when the boom, after a hard day's work, needed a little lie down and a rest from all that rolling around.

 

Just ideas, guys, until we hear something definitive.

 

Tony

[Doreltomin]

Hello friends, that's a very interesting discussion, so here's my two cents:

 

Incidentally I have seen such a thing as a boom rest. Not in real life (as the ship burned down during WW2), but in several old photographs, one of which I attached here a crop. The ship was Romania's first Training ship, a brig called "Mircea" (I) and was built by Thames Iron Works and Shibuilding Company, Blackwall near London in 1882. Please see for yourself the boom rest in the attached photograph. Please note that this is on a 19th century ship and moreover, a composite one (that means wooden strakes over iron frames) so the support itself is also made of iron. My own understanding was that the support is not a permanent fitting there but it can be folded and either lie flat on the deck or be put away on stowage when not in use. One thing is certain, there's just one such thing and is right in the middle of the ship, not on a side!

 

Hope this helps!

[tkay11]

And am I right in thinking, Doreltomin, that the boom is firmly lashed to someting just in front of the rest, or is that parallax error?

 

Tony

[Jim Lad]

I would say definitely a boom crutch.  The fact that lines cross on the plan is not a definite indication that the crutch was outboard of the rail, as draughtsmen of the time often crossed lines which, by strict modern convention, shouldn't have been.  This is clear from some of the lines shown on the detail of the plan of my 'Stag', below, showing the lower sheet block; rudder and tiller and deckhouse all in solid lines behind the bulwark (with the rudder and tiller also behind the deckhouse).

 

The red arrows on the pictures below show the boom crutches.

 

John

 

Detail of Stag

 

Contemporary model at NMM

[tkay11]

Nice one, John, and perfect examples. I'm still looking at the Sherbourne plan, though, which shows the crutch well forward of the stern, but so much in the line of the rudder that it makes some sense to think that it would lie either side of the rudder.

 

Tony

[tkay11]

After all that discussion, while looking at my pictures of the Trial at the NMM, I noticed that it had this very boom crutch, which seems fairly centrally placed. Another interesting point is the rail for the boom tackle along the top of the transom.

 

This is more as an interesting add-on to the conversation, rather than to stimulate more discussion.

 

 

 

Tony

[Chuck]

These were actually either centered as you have shown or there were two P & S.  Here is a detail from the Cheerful draft.  They were actually angled to match the angle of the boom rather than facing straight ahead.  They were an extension above the fashion pieces.

 

[tkay11]

Thanks a lot, Chuck, that's very helpful for my thinking about placing a crutch on my build. I'm very much looking forward to the complete Cheerful!

 

Tony

[AntonyUK]

Hi.

This is why I like this forum soooo much.

Little details get questioned and then debated with outcomes that even the designer would be proud of

It just goes to show the extent of knowledge that modellers have.

 

Regards Antony.

[druxey]

The round metal bar carrying boom tackle across the stern was called a horse, I believe.

[tkay11]

Thanks, druxey. In fact I've fitted both a horse and a crutch. I followed Chuck's idea of two crutches in the sense that I placed holding rings for the crutch on both sides of the ship, but just one crutch which can be removed and placed on either side depending on which side the boom feels like resting when it's hanging around in port. This also means that it can be stowed away quite easily when not in use. I have no idea whether this is accurate historically, but it would have made sense if so (I think!).

 

The crutch in the photo is plain boxwood at the moment, but I'm trying to figure out how best to stain it as my walnut stain seems to give a blotchy appearance on boxwood at the moment.

 

You can see the horse just out of focus in the background.

 

Tony

[Mark P]

Interesting discussion gentlemen!

 

Jay's comments about the thingumajig being on the outworks of the ship is correct,  certainly.  Inboard items were shown in red.

 

As a point of interest,  and although I have not yet seen one on a model,  the very detailed (84 pages) contract for the building of 'HMS Culloden'  a 74 gun ship launched in 1776,  contract dated 1770,  states that there is to be 'a hoop and swivel on the quarter,  for the driver boom.'  I interpret this comment as meaning a boom crutch.  This is specifically located on the quarter,  not amidships.

 

It may also refer to a horse,  the metal bar on which the sheet block was allowed to travel,  but these were located amidships.

 

On the cutter model,  the reason for stowing the boom off-centre may be that the tiller was more accessible;  but I am not sure how often a cutter would sail with her mainsail furled.  Alternatively,  is there a hatchway or similar that would be easier to access when in port,  with the boom not above it?

 

Mark P