Dunbrody by Mahuna - FINISHED - 1:48 - Cross-Section - Irish Famine Ship

[aykutansin]

Very very Good job

[HIPEXEC]

Wow! you're making very good progress.

[Mahuna]

Wow! you're making very good progress.

Hi Rich.  Thanks.  Progress has slowed for the last few days due to out-of-town company (I guess New Jersey wasn't hot enough), but I'll be back in the shop tomorrow and hope to post some more updates soon.

[Mahuna]

Part 27 – Accommodation Deck Beams Cont’d

 

I’ve had a few days out of the shop, but now I’m back to work. 

 

Installation of the beams for the Accommodation Deck has continued.  I was able to glue up the next beams – those for the mast partners and the forward companionway – off the model, and then to install them as a sub-assembly.

 

                        

 

To ensure that all beams were properly seated on the shelf, I laid a straight piece of stock across all of the beam ends, and then used the small machinist clamps to press down on that stock.

 

                        

 

The forward-most beam in that sub-assembly also forms the aft beam of the forward hatch.  I assembled the rest of the hatch beams and glued them together off the model.  When they were set they were added to the deck as another sub-assembly, using the clamping arrangement in the following photo.

 

                        

 

Hanging knees were installed in the middle of the forward hatch, and also to the forward-most beam of that hatch.  A stanchion was also installed at the forward-most beam of the hatch.

 

                        

 

The last two beams to be installed were single beams – not part of any assembly.  The forward –most beam has hanging knees and a stanchion.  This completed the installation of the Accommodation Deck beams.

 

                        

 

                        

 

There are gaps between some of the hanging knees and the beams above them.  The gaps can be seen in the photo above, but they are difficult to see when looking at the model – some contortions would be required to pick them out.

 

I’ve been wrestling with a question about the stanchions and I’m open to comments and suggestions on how to proceed:

 

During the period when Dunbrody was built, stanchions were held in several different ways: by standing knees as I used in the model; by iron straps and clasps at the base and top of the stanchions; and by simply bolting them in place.  Unfortunately, the construction plans don't provide any information that would indicate the method of supporting the stanchions.

 

I decided to use the knees because I thought it would look more complete, and I used the proportions shown in some drawings from the Crothers book (the height of the knees is 20-25% of the height of the stanchions.).  The knees looked too big when I first constructed them and I reduced them in size.

 

I’m still concerned that the knees might be too much of an obstruction in the hold. 

 

            

 

            

 

The model is at the point where the stanchions and knees could still be removed and the stanchions redone.  I think if I did away with the knees I’d try to make straps for the base of the stanchions but probably not for the top.

 

If anyone has an opinion or suggestion on how I should proceed with the stanchions (leave the knees in or replace them with straps or bolts) I’d appreciate hearing from you.

 

Thanks for following this build , and thanks for the continued encouragement.

 

[GuntherMT]

Excellent work, and very nice progress Frank.

 

My opinion, based purely on the visual appearance is to leave the knee's.  I think they add a very nice visual to the bottom of the hold area, and ship construction in that era wasn't particularly worried about how the construction affected the movement of sailors (or in this case passengers) in the hold, and the would provide no real issue as far as cargo as the area between the stanchions wouldn't really be much usable space regardless  of the cargo.

[Omega1234]

Hi Frank

 

No opinion, or advice from me. Just sheer admiration!

 

Love it.

 

Cheers

 

Patrick

[albert]

Wonderful, very nice work Frank.

[Mahuna]

Excellent work, and very nice progress Frank.

 

My opinion, based purely on the visual appearance is to leave the knee's.  I think they add a very nice visual to the bottom of the hold area, and ship construction in that era wasn't particularly worried about how the construction affected the movement of sailors (or in this case passengers) in the hold, and the would provide no real issue as far as cargo as the area between the stanchions wouldn't really be much usable space regardless  of the cargo.

Thanks Brian.  My better half agrees that I should leave the knees, so I'm leaning that way.  By the way - the passengers didn't get into the hold, I think.

 

 

Hi Frank

 

No opinion, or advice from me. Just sheer admiration!

 

Love it.

 

Cheers

 

Patrick

 

Thanks Patrick.  I was happy to see Magellan again.

[Mahuna]

Wonderful, very nice work Frank.

Thanks Albert

[druxey]

Coming along beautifully, Albert. The knees (standards, if they are that way up!) look right. I doubt if anything would be stowed along the midline anyway.

[EdT]

Frank,

 

I don't have an answer but will comment.  The purpose of the knees on the stanchions was to allow them to function in tension as well as compression, so if this was part of the design they should be fitted at both ends.  Stanchions on decks above this could be through bolted with long tie rods, but that cannot be done on the keelson.  The knees might be either iron or wood.  My guess would be iron for an English/British ship, wood for a mid-century American ship - but who knows.

 

Ed

[Mahuna]

Frank,

 

I don't have an answer but will comment.  The purpose of the knees on the stanchions was to allow them to function in tension as well as compression, so if this was part of the design they should be fitted at both ends.  Stanchions on decks above this could be through bolted with long tie rods, but that cannot be done on the keelson.  The knees might be either iron or wood.  My guess would be iron for an English/British ship, wood for a mid-century American ship - but who knows.

 

Ed

Thanks Ed.  Since Dunbrody was built in Canada there was probably a mix of Amercian and English building techniques used in her construction.  I'm going to leave them as is.

[Mahuna]

Coming along beautifully, Albert. The knees (standards, if they are that way up!) look right. I doubt if anything would be stowed along the midline anyway.

Thanks Druxey (it's Frank, not Albert  ).  I'm glad I won't need to pull out the alcohol once again!

[captainbob]

Frank, I love that last end on picture.  Putting the shelves with the rolled up blueprints on the deck is a much better place then making the workmen get off the boat every time they need to check a dimension.

 

Bob

[EdT]

1845, Quebec, I'd say wood is a good bet.

 

Ed

[druxey]

Oops. my apologies, Frank. (Excuse: I was always poor at remembering people's names!) I agree: wood.

[Mahuna]

Part 28 – Margin Plank, Upper Clamp, and Mast Partners

 

Since my last post I’ve worked on several odds and ends:

 

Installed lodging knees for the beams holding the Mast Partners.  These knees are mostly hidden by the Margin Strake, so I didn’t take any photos.

 

Trimmed the partial bilge ceiling on frame #35 starboard side – these partial strakes were installed to give the knee a base

 

Pinned the main beams at frames 19, 22, 41, and 44.  I used 1/32 brass rods as functional bolts epoxied in place.  This was done to prevent the forward and aft parts of the frame from spreading.

 

Added a stanchion and knees to the beam for the main hatch at Frame #38 (this was omitted in error).

 

Did some general cleanup and light sanding.

 

I didn’t take any photos of the above work – not very interesting.

 

 

Margin Plank and Upper Clamp for Accommodation Deck

 

The Margin Plank and the Upper Deck Clamp on the Accommodation Deck both have a bevel, which needed to be milled.

 

The Margin Plank bevel is too deep for any of my miniature router bits, so I had to use the tilting table to get the correct angle, as shown in the following photo.

 

                        

 

The following photo shows the profile of the Margin Plank

 

                        

 

The Margin Plank was soaked in boiling water and then clamped in place to dry.  No simulated bolts were used, since the bolting pattern would be hidden by the Upper Clamp.

 

                        

 

The Margin Plank was then lightly sanded and installed.

 

                        

 

The bevel on the Upper Deck Clamp is very small, so I was able to use a mini router bit to cut the bevel, using the routing setup in the following photo.

 

                        

 

The plank was pushed into the router bit from the left, while a piece of scrap wood was used to keep the plank against the fence.

 

                        

 

Simulated bolts were then installed using the process covered in a previous post for other planking, and the clamp was then soaked in hot water and clamped to the hull for shaping.

 

After the clamp was dry, it was lightly sanded, the bolts were blackened, and the clamp was installed.

 

                        

 

 

Mast Partners

 

I made the mast partners as two pieces.  The first step was to rough cut the mast opening on the scroll saw.

 

                        

 

The hole was then refined using a file

 

                        

 

The file I used is a Grobet oval needle file, cut 0.  The oval shape gives me good control on a concave part.

 

                        

 

The opening for the mast partners was slightly off center, so I needed to cut the overall shape to match where the opening should be.  The first step in aligning the partners was to orient the hole on center and mark the edges to be cut.

 

                        

 

The partners were test fit to make sure the hole was still centered.

 

                        

 

As a visual check I wanted to check the alignment of the mast with the partners.  I clamped straight rulers so that they were perfectly vertical with one edge on the centerline, and visually checked that the center of the mast was aligned with the rulers’ edges.  Using two straight edges fore and aft of the mast eliminated parallax in viewing the mast alignment.

 

                        

 

Finally, the mast partners were installed.

 

                       

 

Thanks again everyone for following and for the ‘Likes’ and comments – the encouragement you give me helps to keep me motivated!

[GuntherMT]

Great progress Frank.  I'm going to have to come by some evening after work and take a look at it in person.

[Mahuna]

Thanks Brian.  You're always welcome to drop by.  We'll be leaving for a little vacation around July 20, so it needs to be before then.

[druxey]

Nice simple method for ensuring the partners are on the centreline, Frank.

[Mahuna]

Nice simple method for ensuring the partners are on the centreline, Frank.

Thanks Druxey.  I'm trying to decide how far above the main deck to project the mast stub.  Any suggestions?

[ggrieco]

Always amazed by your precision!! She's coming along quickly! Beautiful Frank!

[Mahuna]

Thanks Glenn.  Likewise, I'm really enjoying your Heroine build.

[druxey]

Try seeing how 6' 0" above deck looks for a starting point.

[Mahuna]

Try seeing how 6' 0" above deck looks for a starting point.

Thanks Druxey -  that will put the top of the stub a little above the highest furniture (a companionway), so it should look good.

[Mahuna]

Part 29 – Main Deck Clamps and Shelf

 

I’ve decided to continue on with the interior sides of the ship before working on any details of the Accommodation Deck.

 

The frames were left oversized during the installation, so they needed to be reduced to their final height.  Before any of the reduction work was done, the planksheer height was re-measured and a corresponding line was drawn on each frame.

 

Reducing the height of the frames meant the removal of as much as ¼ inch of wood on some frames.  The frames were too close together to use any of the saws that I had available, so I used other tools:

 

Where I could do so without risking any damage to the frames or the associated stanchions, I carefully ground down the height using a stump cutter on a rotary device.

 

                        

 

The stump cutter removed a lot of the extra wood, but a ‘kinder, more gentle’ approach was needed to bring the frames down to their proper height.  A 00 cut Barrette file was able to do a good job of wood removal, but the sides were quite sharp and ran the risk of scoring the stanchions, since the excess wood needed to be removed right to the stanchion.

 

                        

 

I tried using a larger pillar file, which had one blank edge.  This edge was thick enough that it did not score the stanchion and I was able to remove the frame wood right up to the stanchion. 

 

                        

 

So my process evolved to removing as much as was safe with the stump cutter and then filing away the rest of the wood with the pillar file.  After several hours of tedious work the frames were all at the proper height.

 

                        

 

The Main Deck is supported by two clamps and a shelf on each side.  The two clamps are separated by an air strake, so I don’t know what the purpose of the lower deck clamp is.  Nevertheless, in keeping with the plan to build Dunbrody as depicted in the construction plans, I decided to install both clamps. 

 

The first of these timbers to be installed were the upper deck clamps, so I made a measuring stick at the correct height for the top of the clamp, and marked all of the frames using that device as in the following photo.

 

                        

 

The clamps were each made of two pieces joined by a hooked scarf, were soaked in boiling water and bent by clamping them in position until dry.  Simulated bolts were marked, drilled, and installed using 22 gauge copper wire that was work-hardened.  The clamps were then glued in place.

 

                        

 

A similar process was then followed for the main deck shelves.  Even though much of the starboard side will be left open, clamps and shelves were installed on both sides to ensure the strength of the hull.

 

                        

 

Once the clamps and shelves had dried overnight, I then felt comfortable in removing the temporary ribbands that had been in place since the framing was completed.

 

                        

 

These ribbands were connected to the frames using wires (which had become pretty annoying as I scratched my arms on them whenever I needed to reach inside the hull).  Removing the ribbands was a simple process of snipping the wires.  Dunbrody now looks like a real ship’s hull.

 

                        

 

                        

 

The device that held the string used to mark the centerline was too short to mark the centerline at the main deck, so I extended the device to allow the centerline to be approximately 1/16 inch above the deck beams.

 

                        

 

In the prior post I mentioned that the opening for the mast partners was slightly off-center.  When I drew the plans for the Accommodation Deck I made the incorrect assumption that the frames were all properly centered.  In fact, the starboard side is farther from center than the port side is.  In drawing the plans for the Main Deck, I need to account for this discrepancy whenever there is a connection between the decks (as in companionways, hatches, and mast partners), but I wanted the plans to also reflect the actual state of the construction.  I needed a device to measure the distance from the centerline to the side for each deck beam, and any rulers that I had were too big to properly measure these distances.  So I used CAD to draft a centering ruler, which I then glued to a piece of stock slightly thinner than the height of a deck beam at the crown of the round-up, or deck camber.

 

                        

 

                     

 

I used this device by aligning the center of the device with the centerline thread while resting the device on the two deck shelves, and then reading off the distance for each side.  After recording the distances for each deck beam I’ll be able to draw a more accurate plan.

 

                        

 

The last bit of the completed work is the installation of the filling strakes on the port side.

 

                        

 

I still need to install the lower deck clamp on the port side, and all partial strakes on the starboard side.  The partial strakes will be installed on the frames bordering the viewing ports and on the individual frames left in place to support the hanging knees associated with the main deck’s beams.  The yellow tape in the following photo of the starboard side indicates those frames that will be left in place.

 

                        

 

Dunbrody is progressing nicely, and fairly soon I’ll be able to start finishing off the Accommodation Deck.  Then the interesting work of building the emigrants’ facilities can be started.

 

 

Once again, thanks everyone – for following, for the ‘Likes’, and for the comments and assistance.

[GuntherMT]

Looking great Frank.  Not much else to say!

 

On the stub mast, have you considered at all doing the full lower mast so that you could include the shrouds and other lower rigging details, or do you want to just leave this completely rigging free?

[Omega1234]

Hi Frank

 

Really nice! She's definitely getting there.

 

Cheers

 

Patrick

[druxey]

Real progress visually now, Frank. That is looking great!

[EdT]

Lovely work, Frank. Setting and holding an accurate deck beam centerline can be tricky.  The centering ruler is a neat idea.  In the 14th picture the ruler appears off center, but the string also appears off center.  Am I seeing it wrong.

 

Ed