Topic: Blue Marlin - Heavy lift semi submersible ship (Read 18948 times)

boatmadman · « **on:** March 04, 2008, 06:32:38 PM »

Not sure where this should be - it going to be a semi submersible, so not a sub, but still a workboat.

Anyway, here is the start of my latest attempt at shipmodelling.

The Blue Marlin was built for Dockwise. They sent me a lines diagram on an A4 sheet of paper for a 224m ship. With the help of a pantograph and plenty squinting I have made some progress.

This model is being built at 1:175 - odd scale I know, this makes it 1.28m x 0.36m so it should be relatively easy to move around.

The last 2 pics from wikipedia.

Ian

boatmadman · « **Reply #1 on:** March 14, 2008, 09:01:59 PM »

Hi,
A little progress tonight, some more frames fitted, and started cutting out holes for tank balancing.

Ian

boatmadman · « **Reply #2 on:** March 27, 2008, 10:22:05 AM »

I intend to coat with epoxy inside and out. Havent decided for sure yet, but I may do all the frames and tank dividers before starting planking.

Been doing more on the tankage, and trying to figure out where stuff will go - this is a bit of a headache!

Some more pics soon.

Ian

boatmadman · « **Reply #3 on:** March 27, 2008, 06:00:43 PM »

Hi,

Well, been working away and thinking a lot. Got the tankage somewhere near how I think I need it.

However, I have realised that at this scale, there is only space for a 30mm prop. Now, my gut tells me that wont cope with this things weight and the fact it is flat bottomed with no keel, so, I have cut a new rear section of keel to allow for a prop up to 60mm, this will require some mods to the rear few frames, but so it goes.

The plus side is that this is now a free lance design!

Ian

boatmadman · « **Reply #4 on:** April 02, 2008, 08:23:11 PM »

Started planking today - it's gonna be a nightmare, lots of tight corners!

I am using a hot air blower to bend the planks this time - quick and easy, even get scorched fingers for my trouble!

Ian

boatmadman · « **Reply #5 on:** April 08, 2008, 08:51:28 PM »

Some more planking progress, but it is sooo slow!

Been haviing trouble getting around the stern post, I must have broken 10 or 12 planks trying to get the bends. Tried heat (wet and dry heat), gentle persuasion, non gentle persuasion but all to no avail. >:(

So, I decided to leave it where I had got to and plank a straight piece from the bottom to under the transom with the intention of backfilling with plank sections - hope it works!

I even managed to punch a hole in one of the planks - doh! Not going to remove and refit another, I will fit a backing piece and fill the hole.

This IS a challenge!

Ian

boatmadman · « **Reply #6 on:** April 15, 2008, 10:26:26 AM »

Its going slowly!

Got some more planking done, the hull shape makes it impossible to plank bow to stern in one length so I am having to plank in sections. Looks a mess at the moment, but they always do at this stage - well, mine do anyway!

boatmadman · « **Reply #7 on:** May 01, 2008, 07:59:16 AM »

Updates? - ok - well, no progress for a couple of weeks cos a cruise to Norway got in the way

Also, this week I got the sail for my 1:1 build, so I have spent some time rigging and sorting that out, nearly ready now so back to the Marlin soon.

Ian

boatmadman · « **Reply #8 on:** May 06, 2008, 02:09:12 PM »

Here we are with an update - nothing spectacular, just more planking. Due to the curves at the bow, I am having to plank in 5mm strips at the moment - takes sooo long!

I have also fitted extra bulkheads in the tanks as I felt that more rigidity was needed given the weight of water it will have to move around.

Ian

boatmadman · « **Reply #9 on:** May 13, 2008, 08:25:52 PM »

A little more progress on the planking.

Ian

boatmadman · « **Reply #10 on:** May 16, 2008, 07:10:05 PM »

Its off the building board! WOO HOO

It will have to go back on though after some internal mods and strengthening!

Ian

boatmadman · « **Reply #11 on:** June 04, 2008, 08:46:02 PM »

Progress at last!

Filling/sanding/filling/sanding carving balsa blocks, more filling/sanding - grrr I hate sanding!

At least now she has a pointy end it looks a bit more like it should

Ian

boatmadman · « **Reply #12 on:** June 09, 2008, 09:14:32 PM »

And here she is with one coat of epoxy and some lightweight cloth on her.

Also, you will see a hole and a dent - well, the hole is one of 4 in the hull for pumping ballast. The dent - thats another story, I dropped a G clamp on her!

Ian

boatmadman · « **Reply #13 on:** June 15, 2008, 04:08:46 PM »

Righto, sanded down after the first coat of epoxy - hate this job, put on the second coat of epoxy. This time I used thin pieces of ply to scrape off the excess epoxy, its surprising how much came off! But after drying, the hull is significantly stronger than it was before.

Then more sanding, washing, sanding, washing etc and now its just about ready for a dust of paint to reveal all the lumps and bumps I have missed.

Ian

boatmadman · « **Reply #14 on:** June 17, 2008, 08:30:40 PM »

Got the first primer coat on tonight, needs a bit more fettling to the hull, but its not too bad.

Ian

boatmadman · « **Reply #15 on:** June 20, 2008, 05:03:46 PM »

Hi,

Yesterday I got all the ballast tanks coated in epoxy, I used fast glass from a well known motor supplies shop thinned with a little meths.

Then I did ballast tank volume and integrity trials.

My rough calculations indicated about 5l per tank, they turned out to be about 4.5l so I am happy with that.

There are a couple of places where there is a little leakage between tanks, but nothing major.

Ian

boatmadman · « **Reply #16 on:** June 20, 2008, 08:22:22 PM »

Umi,

I only put water IN it, not it in the water!

Pumping arrangements will be revealed in due course - watch this space

Ian

boatmadman · « **Reply #17 on:** July 02, 2008, 12:40:23 PM »

Floatation and Ballast test!

She floats and the pumps pump water in and out as required.

Problem - the ballast tanks when full only bring her down to just above normal working level, so, additional ballast is required.

The bow thruster works although probably a bit too powerful on 12v.

Ian

boatmadman · « **Reply #18 on:** August 02, 2008, 08:11:20 AM »

Hi,

Updates... well, been doing a little on separating the tanks and sealing the bow and stern sections, but, I was getting a bit bogged down with it for a while, so hadnt done much.

I decided to have a short break from it and do something different - a hydrofoil refurbishment.

Think I will be back to marlin with renewed vigour next week.

Ian

boatmadman · « **Reply #19 on:** August 06, 2008, 04:13:12 PM »

I have never built a hull with so many holes in it......16 at the last count!!!!

2 for the bow thruster, 8 for the free flooding ballast tanks, 4 for the ballast pumps, 1 for the prop shaft and one for the rudder - hope I havent forgotten any!

I made brass flanges for each of the ballast holes and epoxied them in from the inside and outside.

Ian

boatmadman · « **Reply #20 on:** August 07, 2008, 04:03:15 PM »

Went for more trials in the domestic test tank today - didnt get so far though, the free flooding tanks worked fine, but I had a couple of leaks between the free flooding and pumped ballast tanks, so trials aborted, hull now drying out before leak sealing with epoxy.

Ian

boatmadman · « **Reply #21 on:** August 14, 2008, 11:14:13 AM »

well, after much pulling of hair out trying to find the source of and stop various leaks between tanks, I am now nearly bald, so, am off to Italy for a while to sit in the sun, drink wine, eat food and grow hair.

Ian

boatmadman · « **Reply #22 on:** August 26, 2008, 11:00:45 AM »

Well that worked

A week in the sun, home, another attempt at sealing the leaks and all is now sealed so I can get on with it again.

So, the moral of the story is:

When you come up against a problem that just wont sort out, go to Italy for a week in the sun, come home, try again and bingo....all is well

Ian (with some new hair growth)

boatmadman · « **Reply #23 on:** August 26, 2008, 01:08:49 PM »

Right then, just done another test tank run, determined I will need about 12 to 14 kg of lead ballast. So thats a step ahead.

BUT... 2 steps back

I drowned the engineers!!! the engine room flooded, so thats the next job now - sort that out when it dries out.

boatmadman · « **Reply #24 on:** August 28, 2008, 10:59:46 AM »

Spent a while working out the steering arrangements.

The servo will live in a ballast tower connected by bowden cable to the rudder arms - why? this allows for the steering flat to free flood (avoids having to seal another compartment). Using the bowden cable allows the sheath to run from below the waterline when submerged to above the waterline thus avoiding any water ingress - well thats the theory anyway.

Pics show structure dry fitted.

Ian

boatmadman · « **Reply #25 on:** September 01, 2008, 08:07:37 PM »

Got bored with working on tanks etc so I started on a ballast tower today. This one houses the steering servo and will (hopefully) keep water pout and allow access to the servo. More to be done on it yet.

Ian

boatmadman · « **Reply #26 on:** September 02, 2008, 05:50:51 PM »

Today I have cut off the remaining build supports - trouble is, one was useful as a handle, ah well!

I have levelled the hull frames to allow a deck to lay flat and started working towards sealing the pumped ballast tanks.

I have lain a pce of MDF on the deck to give an idea of what she will look like, and, loaded 2 springers on bard!

Ian

boatmadman · « **Reply #27 on:** September 07, 2008, 07:44:47 PM »

Marlin now has tank tops made for the pumped ballas tanks and engine rom.

The air vent pipes for the pumped ballast tanks are also now in place.

Ian

boatmadman · « **Reply #28 on:** September 07, 2008, 09:52:55 PM »

The air vents are the clear silicone tubing held in place by the 'L' shaped bits of wood. The tube passes through the watertight bulkheads and exits to atmosphere.

Ian

boatmadman · « **Reply #29 on:** September 07, 2008, 10:02:00 PM »

the two forward tank vents will go up through the forward structure and out the funnel, the two rear vents will find a way out somewhere - probably through a ballast tower.

boatmadman · « **Reply #30 on:** September 17, 2008, 03:40:05 PM »

Marlin has had a test in the new madboatworks test tank!

It all went quite well, a couple of small leaks on a tank cover to sort out.

And then I found water getting into the engine room and bows

Now, where the flippin 'eck is that coming from I muttered. I discovered it is coming down the cable conduit. Further investigation revealed that when drilling pilot holes for the tank cover screws, I drilled into the conduit in two places DOH! Fortunately, the cables werent in at that time, so no damage there. Anyway, an easy fix.

Ian

boatmadman · « **Reply #31 on:** September 23, 2008, 03:37:24 AM »

No real progress at the mo, been working stupid hours.

But, been thinking about the superstructure and it will need lots of small windows cut in to it.

How do you all cut windows in plastic so they look neat, straight and regular, bearing in mind this thing is about 1:175 scale?

Ian

boatmadman · « **Reply #32 on:** September 28, 2008, 12:15:55 PM »

Bigford, might be worth investigating that idea, thanks.

Umi, I may be picking your brains soon for detailing at that scale.

Update:

Did a first submergance test last night - all went sort of until... put a small load on the deck, turned around to get my camera, turned back to find Marlin half way to a capsize!!! So, sorry no pics, will try again this week I hope.

I hadnt appreciated just how tender it would be when submerged, I havent put any stabilizing buoyancy in yet, I thought it would be ok in a flat calm test tank!

Ian

boatmadman · « **Reply #33 on:** October 02, 2008, 08:28:55 PM »

Hi,

I tried the punch method and couldnt get consistently straight rectangular holes, also, i found I was having to straughten and re file the punch after 2 or 3 holes.

So, I went for the UMI method - 1 at a time! Took a while but I think its come out ok.

I have taped the bridge wings on just to give an idea of the dimensions of this thing.

Ian

boatmadman · « **Reply #34 on:** October 05, 2008, 07:03:08 PM »

Good idea Andy. However I am putting blocks of foam in the outermost tanks to gain buoyancy - pics to follow eventually.

Meantime, some more work on the superstructure, and started on two cranes.

Ian

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