Scheldt River by Javelin - 1/1250 - Bottle - Dredger

[Javelin]

Well there it is, cat's out of the bag now. 

 

After a lot of thought and a tremendous amount of ideas, bottles and tests, I finally decided upon Scheldt River for my next SIB project. 

Unlike @Glen McGuire, I simply collect bottles instead of going to a liquor store to pick them out. I had a lot of trouble finding a decent bottle for my first SIB (Sea Installer) and actually poured the liquor in a different bottle in order to use the bottle I wanted. So ever since, I'm just collecting decent looking bottles. 

 

And yes, the one with the really long neck looks appealing... The wooden guy lost an arm, so either I fix it, or I try to get him out and use the bottle, since it has an interesting shape! 

In any case, I wanted to use one of the very large ones, trying several ships in it, but it simply didn't look right. Seems those bottles are too large (which leads me to think that I will put multiple ships in those bottles? 

I'm also quite specific about scales, so I actually wanted to put a 1/700 modern ship in it. That would have filled the bottle properly in length and height, but the it would have been a real issue with that neck, cutting the hull in 3, 4 or more pieces just to get it in, simply seemed to much to me. 

1/2000, same scale as Sea Installer and Spartacus would have made any ship too small to fill the bottle, so eventually I decided on something in between. 1/1250 is a rather common scale and would reduce a ship's beam to an acceptable level to fit inside a bottle neck. 

 

Then of course the length wouldn't fill the bottle at all, so I decided on a slightly smaller bottle, é voilà, there we are:

 

 

The drawing is just a drawing of course. Scheldt River is what they call a Trailing Suction Hopper Dredger (TSHD), which is a dredging vessel that drags a draghead on a long pipe over the bottom of a river or port. This dradhead is equipped with teeth and spray nozzles to stir up sediments, which are then sucked up through the draghead and pipe to the vessels hold/hopper. There the sediments are slowing down and sink to the bottom of the vessel while any excess water goes back to the sea/river. When the hopper is full of sediment, the hopper raises the draghead onboard and moves to an area to discharge. This can be done by opening bottom doors or pumping it to a floating line (bow connection) or rainbowing (spraying it up in the air towards a beach, also through the bow connection). 

In short, they are either used to keep rivers/ports at depth or to build islands/ports by bringing sand/sediment to the required places. 

Scheldt River has 1 sister called Meuse River. Scheldt River is a special dredger as she was one of the first TSHD's that were able to run on LNG (cleaner fuel than the regular heavy fuel or diesel). 

 

Although my earlier idea was show her dumping sand from the bottom doors I have decided to try to depict her while dredging. 

Further info about the idea (probably with a sketch) will follow in a later post. 

I've started construction of the vessel itself. Still in early stage:

 

 

 

[Glen McGuire]

Glad to see you hitting the bottle again, Roel!  This looks like it's going to be a fascinating build and you are off to a nice start.  I'm anxious to see the sketch to get a better idea of what the overall project will be.  You continue to choose such interesting vessels!

[Javelin]

Hi @Glen McGuire, 

 

glad to see you're following. 

Here is an explanation on this type of ship and the depiction doesn't differ too much from what I'm going to try (except of course that these ships don't have a pipe connected to their bow while they are dredging). The link is also by the IHC shipyard in the Netherlands where also Scheldt and Meuse River were built. 

 

Trailing Suction Hopper dredger

 

 

 

So basically I'll have the dredge pipe deployed. Obviously due to the limited "depth" of water that I can achieve, the angle won't be very impressive. 

I'll again put sand on the bottom of the bottom, just to the right depth to achieve a width that matches the width of the dredger with pipe deployed. 
Due to the bubble issues with my previous attempts, I'll be mixing the sand with epoxy rather than acrylic gel this time. I checked a few you-tube videos and it seems this is also done by epoxy artists, so it shouldn't give any adverse effects this time. 

 

 

So as before I'm drawing up a sequence and adapt when required: 

 

- Arrange the sand on the bottom with epoxy. 

- insert starboard part of the hull

- insert portside part of the hull, which has the dredge pipe attached (more on that later)

- put the two parts together to form the basic hull

- insert special tool (to be made) that forms a long beam and is fixed on the top of the bottle neck to hang the hull (with earlier attached ropes) 

- pour epoxy, let dry 

- when hull is fixed, use acrylic gel to create tiny waves on the sea surface

- insert aft superstructure

- mount aft crane (still need to check in which sort of position)

- mount main deck level, including opening cylinders for bottom doors and lower part of forward superstructure and pipeline

- mount middle crane 

- mount bridge with mast

 

At first I wanted to create some extra depth by filling the bottle till the middle of the neck with epoxy, I then realised I would only have half of the neck opening for mounting the other parts etc., which would probably not even allow to insert a tweezer inside the bottle... Dumb idea really, but it would have been cool  (unfortunately still no magic skills here). 

 

I don't have the bottle with me, this complicates things a bit, but I did take measurements of the opening, drew the circle out and I can check with some certainty whether parts will fit through or not. 

 

I also saw clouds being made with medical cotton and epoxy, so that's something I'll try to create to mount around the draghead. I'll then insert it, attached to the draghead. I'm also thinking of making some objects on the bottom to make it a bit more interesting (and realistic, as dredgers catch a lot of stuff on the bottom). 

 

In the meanwhile the starboard side received its outer plate and I've started shaping the bulbous bow and stern area. I don't have any filler with me, so it'll have to stay like it is until I get back home for final finishing touches. I will, just like on Sea Installer, apply vaseline on one side of the hull and apply filler on the other, squeeze the parts together afterwards to make sure the center seam is becomes very thin. 

 

I've also carved out an opening in the portside where the dredge pipe will go. I'll explain that idea a bit later on. The pipe itself will be attached, inserted with the outer shell plate. 

 

I'm now working on the inside of the hopper. It has sloped sides and sloped internal divisions to make sure the sand is guided to the bottom doors and doesn't stay behind in piles inside the hopper while dumping/discharging. 

[Javelin]

Figured I hadn't posted any pics of the real ship yet. 

Here is one where she is rainbowing, some vessels have a double connection at the bow and they can choose with valves whether to rainbow or use a floating line. With Scheldt River there is only one connection and if they need to rainbow on a project, they need a special nozzle on that connection. 

Here she's rainbowing over a sort of wall, but often they go close to a dump site in very shallow waters, sometimes grounding the vessel. For that reason they have a flat and wide bottom without bilge keels (so they don't get damaged). They are also rather wide, flat ships in order to keep a shallow draft and widen their operational range. 

 

 

In the above picture the dredge pipe is hoisted onboard, but you can see two sets of tracks along the portside hull. Those tracks lead to a hole underwater, where the pipe connects to the pump suction pipe. The forward tracks are used when the vessel is used in its deep configuration with an extra long dredge pipe, the aft tracks are the ones that are normally used for shallower dredging. 

 

And here you see the dredge pipe when it just came up or is just going down to dredge. 

 

As you may have noticed in previous posts, I cut the hull off center. This is to allow for the extra width of the dredgepipe alongside the portside part of that hull for passing through the bottle neck. The pipe will be mounted in its dredge position, but hinged up to pass the bottle neck. 

 

And here's the idea for mounting her inside the bottle. I'll build a tool that fits in the neck without blocking too much of it, so I can pass the epoxy hose. I guess it'll be made of steel or something else that is stiff an strong. I'll then suspend the hull from that while I pour the epoxy. 

The idea is to make small inverted U-brackets in each half of the hull, forward and aft, so 4 in total. When I insert the hull pieces I'll loop a small rope through each of them, sewing thread I assume. I'll attach those ropes outside of the bottle with some tape (like the real SIB builders do 😁). I'll then attach those to the tool when I insert the tool and adjust the position of the vessel (trim, list, depth). 

Once the epoxy is set, I let go one of the rope and pull it out by the other end. 

Once clear, I'll remove the tool and add the superstructures over those U-brackets to hide them. 

This is the aft superstructure, already prepared with positioning holes (two round centerline ones) and two larger holes to go over the brackets. 

 

And the aft superstructure in place. Also note I've started the sloped sides of the hopper. The transverse piece inside is the separation where the bottom doors are. There are 5 such separations inside, so I'm busy building those now. 

I'm quite limited in equipment at the moment, so I'll try to do as much as I can until I get stuck on either paint or lack of equipment. 

[Glen McGuire]

Good plan insertion, Roel.  Sounds well thought out.

[Keith Black]

 Roel, sorry for being late. What you've done so far looks great and I know she has to be a tiny thing but would you please put something next to her so we'll have an idea just HOW tiny she is. 

Edited November 26 by Keith Black

[Javelin]

Hi Keith,

 

Here you go. She's not exactly tiny, to go into a bottle and in all honesty I've been underestimating the complexity of this little vessel quite a lot. The hull is much more complex than I expected, which makes cutting it for insertion a lot harder than I expected. 
That said, those are the challenges of SIB's. The plan was quite good from the beginning, so in the end I do see solutions to all issues I'm currently encountering. 

For me the main planning is the vessel size compared to the bottle as well as the bottle neck. Modern vessels are much lower and don't fill bottles so well. It's therefore not the height of the mast that determines the size of the vessel, but rather the size of the hull. And it's the insertion of the hull that makes these ships difficult to put in bottles. Once you have a good view on how you'll divide the hull, the rest you can work around. 

The mistake I made with the Spartacus project was the huge amount of things sticking out and the gantry in front that would have made working over it, on the back of the vessel nearly impossible. I'm still not entirely sure if I could have pulled it off, but I'm quite happy with what I did with it later on. 

 

As for your request. Here is a picture with a ruler and a pen. Her bulky shape is quite evident here. These ships don't really ballast the vessel much when dredging, the weight of the empty ship is generally aft due to the engines and dredge pump. This means that they can have quite a larger trim on the stern when they are empty. However, when the hopper gets filled with the heavy sediments, the ship trims quite rapidly towards the bow. To avoid this effect, they have this funny "fat lobe" bulb on the bow. Not very elegant, but efficient nonetheless. 

Here are several parts. The forward superstructure will be glued to that deck. The bow part of that deck is however too wide to fit through the neck, so the outer part (In which I will also insert the bulwark) will be glued into the pieces of the hull, while I will probably make a cut around the superstructure (to partly hide the seam). 

 

This upper deck will also support the dredge line, a crane etc. 

The bridge with mast will go on separately, probably the last thing to go in.

The largest parts are done, so I guess I'm nearing the stage of the finer details now. Unfortunately I've forgotten my tweezers... Real smart for a builder of these small scale models! 

I think I'll find a suitable one in the ship's hospital to continue with the detailing.  I still need to refine the holes in that upper deck first. Then I'll add a coaming around the hopper. 

 

[Glen McGuire]

11 hours ago, Javelin said:

I've been underestimating the complexity of this little vessel quite a lot.

Compared to the piping on your tanker, I figured you could do this one in your sleep!  Just kidding, Roel!  This one offers a whole different world of challenges, as you have described so well above.  Looks to me like you are on a solid track though.  Onward thru the fog!

[Javelin]

Through the fog it is @Glen McGuire, 

 

Without the bottle I'm sort of hoping things will get through the neck... 

One of the things I hadn't decided on a straight path yet was the mounting of the top deck or at least where and how that seam would run. Part of it will be hidden underneath the forward superstructure, but another part won't. On the starboard side, the dredge pipe runs along the accommodation block to the bow and for structural reasons I decided to make the supports of that pipe and rest them on the deck. I guess I could also leave them hanging, but that would be a risk during entry of the bottle and during installation as there would be no way for me to rectify any of it once it's in the bottle. 

Here is where we are today, I've finally started with the finer detailing on that aft superstructure. The forward part is generally finished. However the bridge is kept loose as it will otherwise be too hard to paint and put the windows on (black marker, just like the Sea Installer). 

 

There is a coaming around the hopper opening now, still need to do the aft edge. The dredge pipe will then be built and connected along this deck, all the way to the bow. 

 

 

With a fairly good view on where this will go and only some detailing/finishing to go, it was also time to think about how to support the bottle. Once again I have two different ideas, the first and most intensive, would be to mount the bottle on top of a draghead (scale and with part of dredge pipe or not still to be determined). And the draghead would then be laying on a sandy base. Sorry for the crappy drawing, I haven't studied the construction of a draghead too well yet. It's tricky since there is no proper support on top of it. 

 

The second idea is by far the simplest and is basically a stack of sheets over which I would make a "mountain" of sand in which the bottle lays. I can use my regular acrylic gel-sand mixture, which will stick well to the glass as well. 

 

I assume I could even make a third idea by simply sticking sand-acrylic to the bottom of the bottle until I get a flat bottom to prevent the bottle from rolling. I could match that also with the contour of the sand inside the bottle?! 

In any case, something to think about in the near future. I guess the draghead plan is the least likely, since it will be time consuming and difficult to get the bottle steady on top of such a structure. Apart from a draghead, there are no real pieces of equipment that are typical for a TSHD. A dredge pump is less typical, but perhaps easier to adapt as a stand. 

 

Let me know what you guys think?

[Keith Black]

Roel, I like option #2 but the contour of sand inside the bottle sounds interesting. This is a spiffy little project. 

[Glen McGuire]

2 hours ago, Javelin said:

I guess the draghead plan is the least likely, since it will be time consuming and difficult to get the bottle steady on top of such a structure.

Someone once told me, "It's basically the point of SIB's. If it's not hard or just straightforward, then what's the point?" 

 

Oh wait.  That was you, Roel!  You posted those very inspirational words recently on my Flying Dutchman/Black Pearl log.  Even though I have no idea what a draghead is, your sketch looks quite intriguing.  I vote for that option.  

Edited December 3 by Glen McGuire

[Keith Black]

13 minutes ago, Glen McGuire said:

I have no idea what a draghead

 Wasn't that an old TV show? 

[Glen McGuire]

19 hours ago, Keith Black said:

Wasn't that an old TV show? 

It actually reminded me of a word we have here in Austin - Dragworms.  The main street that runs on the west side of the University of Texas campus is affectionately known as "The Drag".  It's full of eclectic bars, shops, street vendors, etc.  But it also has its share of unsavory characters that are always milling about and everyone calls them Dragworms. 

[Javelin]

Before this gets derailed and the dredger has to tow a pod of whales in the bottle, here are some pics of the draghead. 
Since this is not the type of dredger I work on, I don't have that many reference pictures on this ship. Perhaps that is a blessing rather than a curse, considering the complexity of this ship. 

As you can see the upstanding parts on both sides could act well to hold the bottle, however the pipe in the centre would leave the forward part of the bottle unsupported, with greater risk of it rolling off. 

In this shot you can see the row of teeth at the top of the entry. 

So basically it's a vacuum cleaner nozzle. They adjust the visor, which is the openin/jaw where the teeth are located to create a bigger or smaller opening and it also has these jet nozzles. 

This type of dredger catches a lot of bombs (depending on the area they are dredging in of course), which then get stuck in the visor. Always a surprise when that head comes back up, occasionally the bombs just fall out once the head is back onboard, but as far as I know, most of the time they are stuck inside. In any case, they have to stop dredging and contact the navy to come and get it out. 

 

 

 

You'll also be surprised to find out these are generally operated by a single person, the dredging part, putting the pipe overboard etc. is very automated, so he mostly concentrates on navigation once dredging is started. Of course there is a crew onboard for the machinery part as well as the maintenance part of the dredge equipment etc. In some areas with very dense traffic they are obliged to have 2 people on the bridge, one for dredging and one for navigation. 

 

 

 

[Javelin]

Still plugging away. I believe I might just be about finished with what I can by the time I go back and home and continue this build in earnest. 

First my actual way of checking whether things will pass or not. As far as I noticed, I will probably need to remove the portside platform from the highest deck, since it makes the deck too wide to pass. However I will only remove once I have checked with the actual bottle. The bottle has a rather short neck, which might allow me to wiggle the complete deck through. 

The aft superstructure can clearly pass. The numbers on the right are boxes I've drawn in the bottle opening and then measured for easy reference. It makes planning a bit easier. 

 

She has now received her bulwark, forward structure for the discharge pipe and the first gantry for the suction pipe. (the second one you can see on the foreground). 

The forward structure will not be mounted on the deck, since then it won't pass the bottleneck, so it will be attached to the discharge pipe (along with more supports), which in turn will be connected to the main deck and lower part of the superstructure. The bridgewings, bridge and mast will then be a separate part that is placed on top of that. I'll definitely take pictures of the separate parts when I get further in the build. I can only begin to assemble those when I'm painting.  If I'm not mistaken I'll end up with 5 main pieces to assemble in the bottle (7 if you count the cranes as well). 

 

[Keith Black]

 Good stuff, Roel. What do your shipmates think of your modeling? 

[Javelin]

Hi @Keith Black, 

 

I'm keeping this one below the radar, most of them don't know. There is a long-standing feud between the TSHD guys and CSD (Cutter Suction Dredger) guys. It originates from the days when CSD's were generally stationary dredgers, only moved from one spot to another with the help of small support craft (much like Lula). In those days the TSHD guys were the civilised people from Maritime Academy, while the CSD guys were short-tempered construction workers. TSHD guys always regarded CSD people as crude retards, while CSD people regarded TSHD people as softies (I'm expressing myself light here)...

Nowadays however, with self propelled CSD's, the crew on these CSD's are also recruited from Maritime Academy and/or are industrial/civil engineers that took a maritime education on top of that. 

That said, there are still some old school people around to keep the feud alive, but the younger people amongst us consider it ridiculous. It does still mean I have to be careful not to be called a traitor on my CSD. 

 

So, finally time for the dredge pipe. I was lucky to have the correct diameter or brass rod with me for this one. I've also in the meantime completed some containers and both crane jibs. That means I'm basically finished as far as I can get for now. 

The dredge pipe will also be detailed a little further with the smaller diameter jet pipe etc. The part in the middle is a swivel part where the lower part of the pipe can bend in and out. Also near the ship's hull there is a piece of flexible pipe to allow the dredge pipe to move transversely. This happens when the suction head reaches a harder piece of soil, where it will automatically slide around by the resistance of the tougher ground or when the dredger makes a turn while dredging. In those cases the dredge pipe will move. They will of course always try to avoid having it going underneath the ship or too far away from the ship. 

As you can see I made a small hook at the upper end of the dredge pipe, this fits inside the whole I made behind the shell plate (which you can see in one of my previous posts). Once hooked behind the shell, the pipe can move up and down, but stays in place. 

 

 

 

[Keith Black]

Roel, thank you for the insight. 

[Veszett Roka]

From the XXXL Chaconia to the XS dredger - with same precision. Extraordinary, Roel.

...and how i hated the same Dell Latitude laptop when i had one Now a newer model i have and it is even worse, i started loving the old one.

[Javelin]

Thanks guys. 

The Dell's ok, but I don't need to use it so much, so I'm not bothered anyway. 

 

Small update again. Somehow, because the road was clear, I kept postponing the "hooks" for hanging her in the bottle. Since I'm reaching the end of what I can do, I decided to make them (but without gluing for now). 

So here they are in place:

 

And here they are already partly covered the way I envisioned it from the outset. I did decide on a single one forward, since the smaller accommodation block didn't leave much space to cover a 4th one. In any case, anything you suspend or hoist is always only supported by 3 legs, so 4th one would be redundant. Once they are glued, I'll make a hanging test with the dredge pipe connected to see how it goes. 

 

 

Additionally I had to drill the stern thruster in the aft skeg between the propellors and also made the shaft/propellor skegs as well. The props are protected by tunnels (don't have the proper diameter rod with me to make those) and of course there are rudders behind them, which would be too fragile to put on for now. 

 

 

[Rick310]

Nice job!

Rick

[Keith Black]

 Roel, Merry Christmas and Happy New Year to you and yours. 

[Javelin]

Thanks Keith, 

 

And a (belated) Merry Christmass and (future) Happy New Year to you all. May you all celebrate these days with friends and/or family and enjoy the moment! 

 

As for the model... Well, I did succeed in doing something on it since arriving home, but not much. With Christmas etc. it's entirely stopped, we'll see for how long. 

 

In any case, at home I did have the full array of tweezers etc. available, so I did some further detailing on the superstructures.

At the same time, I applied Milliput epoxy filler to the bow and stern areas to make the transition between several pieces of styrene a bit more smooth and to get a better seam between the two halves. 

I'm not entirely happy with the seam, but I've done to attempts now and I guess it'll have to stay like it is. For future builds (if any) I'll definitely make a flat plate on both ends of the joint and build the hull around that. In this case, by cutting that hopper in 2, this method was not practical.

Being home also gave me access to the real bottle in order to test fit a few things. One of the unknown items was the support of the aft crane. It's located near the outside and sticks out quite a bit, which meant it could have caused an issue in the bottleneck. I'm now happy to have it fit, making it easier to mount the crane afterwards. 

 

I also discovered that the aft, longest gantry for the dredge pipe is sticking out a bit too much and won't fit in the bottleneck, I still need to think of a solution for that. 

 

And here is the hull next to the bottle. She will nicely fill the bottle, perhaps a bit too much. This is after application of spray putty, I will sand it smooth before putting any paint on. Before I do that, I'll first need to install more details on the aft, including prop tunnels and rudders. 

The anti-fouling line is drawn, it's not parallel to the keel, since these ships are very heavily trimmed on the stern when empty and apparently they decided to apply this trim to the anti-fouling as well. 

 

 

 

I've also tested the top deck over the hopper and my earlier idea was correct. The platform on the port sticks out too much and it won't fit in the bottle this way. The idea is now to clip that part off and fix it to the hull half. It'll then also act as a good guide to get that deck properly aligned. 

 

That's it for the time being, not sure when the next update will come, nor what it will show...

[Glen McGuire]

1 hour ago, Javelin said:

She will nicely fill the bottle, perhaps a bit too much.

It's hard to tell just from the pictures, but my concern would be that the bottle is not deep enough when lying on it's side.  Even with the epoxy water reaching all the way up to the bottom edge of the bottle's neck, will there be adequate depth for the bottom of the ship, the dredging apparatus, and the sea floor?  I would want to make sure that everything that's under water is clearly visible since that will be such an eye-catching feature for observers.  With the thickness and curvature of the glass, I'm wondering it you will have room.