The Ship Model Forum

Well here's the next one. Increased the scale to 1/400 now, since it's a small vessel. Was supposed to be a quick-and-easy kind of build, but after a couple of days of building I have a different opinion

A split barge is used in dredging to be able to reach shallow places and be able to unload very quickly (high turnaround), they're used when a floating pipeline to a dredging vessel isn't possible (too remote, too much traffic etc.).
They're very simple ships, practically a floating box with minimal mooring equipment and accomodation. That's what I thought

With increased size of the actual dredging vessels, split barges also had to evolve to full size seagoing vessels. The DEME (company with nice green ships) fleet initially operated Sloeber and Pagadder as side-kicks to the cutter suction dredgers D'Artagnan and Ambiorix. With the arrival of Spartacus (nearly double the capacity of D'Artagnan/Ambiorix), they needed bigger Split barges. Those became Bengel and Deugniet. (all of those names are Dutch words for rascal or scoundrel).

As can be seen below, the hull splits, the funnel casings go with it, but the accomodation stays straight...





So easy enough, I'd build two half hulls without giving it much prior thought. Then of course I discovered I needed to build that hopper/cargo hold in the centre, which would leave me with little longitudinal strength and of course a bent keel. In a normal case I'd use a 1.5mm bottom plate to straighten things out, then add the frames and build the hopper.
However, the hopper leaves little in the centre to cut and attach to such a bottom plate.... So I went for a 0.5mm bottom plate.
The strength and straightness was eventually achieved by building that hopper as a sturdy box inside the ship. The frames in that centre part aren't very useful anyway.

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The merchant shipyard

Nice to see you take on a new project, Roel. I do wonder what the people naming these ships were drinking. Lamme Goedzak? Brugse Zot?

Brilliant!!

I love your building of these modern ships that very few people know about
( apart from professional seafarers like you!)

-- leave alone actually make miniature models of them !

BRAVO for tackling the lesser known!

JB

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....I buy them at three times the speed I build 'em.... will I live long enough to empty my stash...?
http://www.modelshipgallery.com/gallery ... index.html

IPMS UK SIG (special interest group) www.finewaterline.com

Thanks Jim and Pieter,

the idea of this build is of course not a regular display. I will attempt to show it in open configuration with the support being a pile of sand pouring down from the hopper. It idea would be to have a transparent plate inside the hopper and one in a straight angle forming a T-shape. The plates would then be treated with a sand-acrylic gel mixture (like I used on the bottom of the Living Stone diorama). Probably I'll add some milliput (painted brown) at top and bottom to give a hill-effect. I'll also see if some dyed cotton wool at the bottom would give a sense of turbulence. I'll be testing that set-up separately before applying it to the model of course.

In the meanwhile it was time for framing.
The holes for and aft of the hopper are the compartments that house the 2 big hydraulic cylinders that open up the ship.

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The merchant shipyard

Interesting concept to split the whole ship. I have seen hopper barges, where the bottoms open (actually a concept was used already in the 18th century to support the mud-dredgers), but not this design.

In German we also have 'Bengel' and 'Taugenichts' ...

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Eberhard

Former chairman Arbeitskreis historischer Schiffbau e.V. (German Association for Shipbuilding History)

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Again a very unique and special subject (that I didn't know existed...), that will make for a very interesting display.

Looking forward to seeing this one develop further!

... another type of ship that splits in the middle, are those barges designed to catch floating oil-films. They are hinged at the stern, open to a V-shape, suck the oil up and separate it out for storage in tanks and later disposal.

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Eberhard

Former chairman Arbeitskreis historischer Schiffbau e.V. (German Association for Shipbuilding History)

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Hello and thanks for the comments.

A lot of dredgers (all of the Trailing Suction Hopper Dredgers) still have bottom doors. However, the problem with doors is... that they are doors . They open and therefore stick out underneath the hull. In a lot of cases dredgers are operating in very shallow areas with (sometimes) intended groundings to get the sand where it needs to be (building islands like in Dubai or making new area for airports or port terminals). This means the doors get frequently damaged by either opening and hitting the ground or simply getting damaged during beaching of the vessel. And when doors are damaged they often don't close properly, resulting in loss of the "cargo".

Split barges don't have that issue, the moment the barge opens, it loses a lot weight and rises quickly. Also opening doesn't really increase the draft of the vessel.

On to the model. Lots of progress made again. This hull needed a lot of preparation before application of the putty. Bulwarks need to be placed first, also the recessed anchor pockets (don't want to damage the anchor or mother vessel during approach) as well as the straight parallel body area as well as the bilge area (flat in this case, not curved as usual).

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The merchant shipyard

So it was time to apply the milliput cover and shape the bow and stern areas. Even after so many models I have never succeeded in doing this in one go. After sanding there are always dents or places where I need to add Milliput. On the other side, you can't put a huge blob of it everywhere as that would take a long time of sanding (and more risk of damaging the styrene structure in the process).

Based on below picture I assumed the hull was narrow enough to have only the bottom plate as a bow thruster tunnel bottom, however after sanding it just didn't seem right. After revisiting some info, I did figure it needed a real bottom. I put a small 0.5mm bottom plate on the tunnel, then inserted a beam the side of the tunnel to support everything and applied more putty to smoothen the whole thing with the rest of the hull. Now it seems right.
Additionally it seems the suction of the thruster is from the bottom, and use of the thruster is simply directing the jet towards one side or the other. There is also only 1 thruster, the other part of the hull simply has a tunnel. This type of bow thrusters is often used in inland navigation ships, occasionally also with an opening forward (like a 3-way valve) to help in stopping the vessel.

The hole in the bottom of the model is an overflow, a second one, on the starboard hull part is aft. You want to move sand/stones, not water, so there are two adjustable overflows which allow the material to settle while the water flows back to the sea through these overflows via the bottom of the vessel.

Currently I'm somewhat stuck on the hull due to lack of spray putty which I use as a final coat before sanding it very finely. Continuing on superstructures and base first now.

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The merchant shipyard

Wonderful how you create these unique subjects from nothing but bits of plastic and putty!

What spray putty do you use?
I have used Motib spray filler for this task before, and was quite happy with it. It is easy to find in the usual hardware stores.

Cool, another interesting offshore construction ship!

I have known such designs only from polution control ships of the German Navy:


https://en.wikipedia.org/wiki/Bottsand-class_oil_recovery_ship

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Hi Marijn,

doesn't look exactly the same, but it is practically the same product. Mine says "Spray Putty" and is also from Motip. However my regular hardware store is out of it and the big chains like Gamma or Hubo don't have it. It's generally located with car body repair stuff and not with the Motip spray paint rack. No luck so far. However I'm continuing the build on different parts.

Maxim,
The German ship looks interesting as well, although Bengel splits at the bottom rather than the stern.

First I did a Sand test with the hull to see how it would come out. Secondly I already produced the base for it. Chose for an irregular base with an upstanding piece of Vivak plate. Initially I was going to make a full curtain, as shown on the test, but then I decided to first try with a partial curtain, like in the very beginning of dropping, creating a transparant piece between the actual bottom and the sand curtain. If it doesn't look right, I can still make it a full curtain to the bottom.
All major superstructure parts (including the forward deckhouses) are now built in the rough form, time to start detailing them. I'm also busy with the aft thrusters and final shaping/sanding of the hull. I will then first apply the spray putty and only after that I'll start making the fender framework on the hull as well as the holes in the bulwark etc.

In the meanwhile I also found a good movie of what I suppose is either Sloeber or Pagadder, one of the older sisters, which shows the whole project from loading from a Cutter Suction Dredger towards the discharge/opening of the barge.

https://youtu.be/KBoPBlLRIr0

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The merchant shipyard

One could lightly tint acrylic gel and built up the cloud of material dropped from the barge - bottom up and with a lot of patience, as the layers cannot be too thick to dry.

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Eberhard

Former chairman Arbeitskreis historischer Schiffbau e.V. (German Association for Shipbuilding History)

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Thank you for the video! That illustrates it well - as do your last photos of your model!

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absolutely brilliant!

most excellent concept and realisation of a concept

justa thought

could you replace the acrylic plate with the sand ( infused with CA in the centre )
as a ( spreading ) column only --?

I think it would have sufficient structural integrity to keep the whole diorama up...



JB

_________________
....I buy them at three times the speed I build 'em.... will I live long enough to empty my stash...?
http://www.modelshipgallery.com/gallery ... index.html

IPMS UK SIG (special interest group) www.finewaterline.com

Hi Jim, thanks for the kind words.

Not sure on that plan. I believe the CA would dry too quick to get to a decent result. With the acrylic, I just mix the sand in, like you would mix paint and then apply it. Then there are 2 options, or you leave it be, and you get a wet sand look, or you just keep adding sand on top of it, later on remove the excess sand, and then you have a dry sand look.

I tried to peel off the acrylic mixture, but it's too flexible to stand on its own.
In any case, I have two options, 1 is to make a partial curtain, simulating the beginning of the dump, or a full curtain. I'll try the first option first, see what it looks like, and if I don't like it, I can still complete the curtain all the way down. Below is the test piece for this.

Also started on the base of the propulsion pods. Each hull half has its own engine room and own propulsion pod. They are mounted a flat base plate to enable a smooth rotation.
I will have to finish it with milliput, along with some tiny blemishes, before I apply the spray putty.

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The merchant shipyard

Succeeded in making some smaller items, like hatches and small deck houses as well as the angled roof of the bridge.
Additionally I've finally obtained the spray putty, from a car store and continued on the hull including the aft bulwarks.

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The merchant shipyard

If the bridge is on it will start to look like a proper barge I think. Very nice, also the 'curtain'.

Hi Pieter,

in previous pictures the "curtain" (which is basically steel fendering to protect the hull against damage from mooring against a rapidly swinging mothership), wasn't attached yet. It was just drawn on the hull. I then scribed it in and laid a 0.3mm straightened copper wire in it.

Due to 1:1 scale work, this project is on the back-burner. However, I did install the curtain and aft bulwarks on one side, and I'm slowly continuing with the second side. I'm nearly ready for paint. Also been testing more green-yellow mixes to get closer to the actual DEME colour. It was an issue with the Living Stone build and still remains an issue now. On Living Stone I used a Motip Spray can, but that was glossy and too thick, so I want to avoid that now.

You can see the waterline also marked on it. Since the ships have a very shallow draft forward when they are in empty condition, their anti-fouling is painted accordingly.

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The merchant shipyard

How did you do the scribing in? Do you used a ruler to guide?

It appears to be difficult because of the bending of the hull there.

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