Forum Marinearchiv

Modellbau => Bauprojekte => Bauberichte inklusiv Feedback => Thema gestartet von: wulfing am 07 Oktober 2018, 20:27:30

Titel: Seehund Trailer Scale 1/35
Beitrag von: wulfing am 07 Oktober 2018, 20:27:30
Hi everybody,
First of all, I have never done a Work-In-Progress (WIP) before and secondly I intend to show you the build only. This WIP will deal with the Seehund trailer, since there is no commercially one available around (unlike the Biber and Molch). I take great interest in the Seehund midget submarine and the men of the Kleinkampfverbände who operated them in the last stages of the war. So, I thought I would share this with you.

Some research: I know of only 5 photos of practical use to replicate a Seehund trailer: 2x HMA, 2x IWM and 1 grainy Unknown. The HMA show the same trailer from different angles including a rear shot. Key features are the angular upper frame, the double main support I-beam, the extra wheel rim and the apparent lack of torpedo supports (?). The IWM photos show a different trailer: rounded upper frame, single support beam and close up views of submarine clamps & torpedo cradle/saddle carriages. The Unknown trailer photo looks similar to IWM, however the entire trailer is in shadow. Despite that it is a good photo to extract lengths and approximate position of the clamps.

The trailer I am building will be hybrid of both: angular upper frame and double support beams + central keel support beam and torpedo support cradles/rails + a heap of guesswork on my part. As well as reinforcements wherever necessary since the VP Seehund (made of resin) weighs as much as the real thing!

The donor kit for the trailer is Einheitsanhänger 5t by Bolddivision: wheels, leafspring suspension, axles, brakes, turntable, the drawbar and part of the frame were used (Elite Models also sells various WH trailers). The white plastics are from Plastruct, since they sell I-beams with heights of 10mm and over. For the main support beams I choose to use BSP-18: an I-beam of 14,3mm in height (500mm IRL), in retrospect BSP-16 (12,7mm = 440mm IRL) would have been better perhaps. Other items: AFS-2 angle, BFS -5, -12 I-beam, HFS -5, -6 H-beam, UFS-2 & -6 U-beam, MR-25 rod, MS-810 strip, TBFS-3 tube and VS-?? tube/pipe saddle (i do not know which one yet). In addition: 1 and 1.5mm plasti-card.


Photo 1 (2666)
The finished wheels/axle/brake. The wheel/axle interface is reinforced with 1.5mm diameter steel rod: I drilled the hub and the axle with a hand drill (see upper left).
The forward suspension assembly (upper and lower part). The upper part is reinforced with BFS-5 I-beam to match the HMA pictures. More I-beam will go on the onside of the resin frame. The spacer ring (upper left on cutting mat) should not be used. Because of that: part 6 of the Bolddivision kit (the triangular supports of the rear suspension assembly (on right side, upside down) need to be shortened by 3mm. I can recommend a fine toothed sawblade.
The grey resin frame is cut in two. Also visible is the BFS-18 I-beam.

Photo 2 (2670)
I glued two provisional cross-beams to ensure the I-beams remain at straight angles during construction; they sit at the approximate position where the foldable clamps will be on the outside. The connection plate between the I-beams and the wheel/turntable frame is made of 1,5mm card and strengthened with 1,0mm card on the inside. Note that no upper and lower flanges are added yet and reinforcement card not yet trimmed). The black Xs are a plate-extension which will sit snug (aka superglued) in the upper wheel/turntable frame (see photo 3 (2669) loose test fit).

At this point I am realising that the main support beams might be too tall (I had already accepted the fact that the upper and lower flanges of the beam are in fact too wide) and also that I should reconsider my earlier decision of omitting the slight curve in the lower part of the I-beam both front and back.

Photo 4 (2672)
A test fit of sorts: the main I-beams have been cut down to a length of 23cm; this will be not be their final length (which is 17 cm). Right now they end where eventually the trailer will end: around the same height as the leading edge of the dive planes. The pencil marks on the Seehund is where the clamps will touch the hull. This is an important benchmark to extrapolate other distances.

Photo 5 (2673)
More BFS-5 I-beams to buttress the back frame assembly. I glued a HFS-5 H-beam above were the axle is going to be. The research photos allude to some sort of construction above the axle, that stiffens the frame and to which the support beams/beam are/is connected. This is midway assembly: the I-beams will be cut flush and then using a grinding disc on rotary tool (dremel, proxxon) I slice between the I-beams to make a slit for the plates to sit snug in. The main support beams are cut to length (17cm). The connection plate is again made from 1.5mm card and braced with 1.0mm card on the inside. The angle is less steep compared to the front: a connection plate template is seen in the lower right (5mm squares). After cutting, the connection plates (all 4) need to be trimmed down a bit on the diagonal sides to accommodate the upper and lower flange.

Photo 6 (2674)
A rough mock-up, which defiantly stares me in the face: decision time. Leave the I-beam as is or put in that curve in the lower part of the I-beam on both ends. And BTW: callipers are indispensable in this project.

That's all for now.
Next up: put in that curve and start working on the crossbeams.
Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: wulfing am 09 Oktober 2018, 11:22:38
Hi everybody,

Continuing with the trailer

Photo 7&8 (2679&2680)
I put in the curve: I cut/sawed out a sliver of a triangle with an opposite side of 2mm and an adjacent side of 60mm for the front and 30mm for the back (along the lower flange). Glued the flange into its new angle, gap-filled superglued the sides, tidied up the connection plates. There are still vertical plates/strips to be added where the bends start: the HMA photos show that these vertical strips fortify the I-beam and support the arms onto which the clamps are located (see photo 9 for frame overview).

I replaced the inside I-beam on the turntable frame with a UFS-6 U-beam. Between this U-beam and the H-beam on the back assembly sits the keel support beam made of UFS-12 I-beam. To make sure the rear frame was a square again I added a #6 U-beam underneath the bottom of the rear assembly to add strength and rigidity. Next came the upper and lower flanges: made of 1mm plasti-card. I am not sure I like the upper ones: constructed out of one piece of strip. It seemed like a good idea at the time; however I might end up making a cut instead of a bend. At this point it is all very rough: there is a fair amount of filling and sanding ahead.

Photo 9&10 (2685&2686)
To make the clamp support arms I cut two 60mm long pieces of HFS-5 H-beam, removed (in the middle) 10mm of upper flange and plate and glued it in place. A drop of thin superglue was added where the H-beam and the keel support I-beam connect. The location for these support arms was determined by looking at wartime photos and guestimate. In this case the forward arm sits 68mm from the front topbend in the I-beam and the rear 38mm from the rear bend (there is about 60mm between support arms). The BFS-5 I-beams in the middle will act as extra backing for the torpedo-carriage rail and an outer rim strip.
I did add the aforementioned vertical plates (12mm high, 3mm wide and 1mm thick); no photos yet.

Next up are the clamps and the torpedo carriage. That update will take longer because I have to wait for the parts to come in since I decided to make the clamps out of two U-beams instead of one H-beam.
Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: wulfing am 25 Oktober 2018, 15:33:52
Hi everybody,
So, we’re back. Thanks to Track & Trace I had the “pleasure” of (virtually) watching my bits of plastic sitting on some Custom’s official’s desk for two weeks. The bits are UFS-3 & 4 U-beam, AFS-3 Angle, 2x2.5mm Strip and VS-24 saddles.

Continuing with the torpedo carriage: in Photo 11 (2695) you can see the VS-24 saddles in dark grey ABS plastic. You can glue two together and trim the excess, and so on. I glued two together and made replicas using silicon-RTV and PU-resin. The saddles are glued onto 2x2.5mm strip 85mm long. In the plastic bag are the wheels, made up of 2mm diameter disc, then a 3mm diameter disc and then a 1mm wide / 2,4mm diameter rod (the discs were made with a punch-&-die set). The wheels were glued just below the middle of the strip and centred with the saddles.  I have since replaced the 4 strips inside each saddle with 0.5mm thick / 1mm wide strip.

Photo 12 (2705)
I used the Bronco Seehund for a mock-up of the whole affair. I have replaced the 4 support arms with newer ones of 90mm in length. I made a mistake cutting the older ones too short because I wrongly calculated the height of where the clamps will support the submarines hull, which in turn affects the length of the support arms, because the clamps are in a fixed angle of 68-70 degrees.

Photo 13 (2706)
This is the hard part: carriages, rails, sub+torps, support arms and future clamp locations all come together and everything needs to be perpendicular and/or parallel. The main H-beam supports were cemented in placed. I cut liberal lengths for the angles/rails (20 cm) and glued them on the carriage-wheels. Then placed both in the approximate position, placed and centred the Seehund. Marked off the outer rail on the H-beams.

Photo 14 (2708)
Top view of the end result. The angle-rails still need to be cut to size and an endcap, and currently they run all the way down to the back, hanging over the rear bumper of the trailer. It is not entirely clear where the rails end exactly, but it seems somewhere above the axle, or at least before the dive planes of the Seehund, the leading edge of those sit just above the rear bumper.

Photo 15 (2709)
Birds eye view. I found using thin cement (and holding my breath) was a requisite when fixating the support beams and rails. But what really helped was to sit down and think about how to break up this build process in bite-sized bits.

Next up is finishing the rails and start working on the clamps.
Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: wulfing am 03 November 2018, 19:28:36
Hi everybody,
Just a small update showing you the addition of L-angle endcaps on the rails and a small T-shape support arm underneath the rear portion of rails (Photo 16 (2716)).

I proceeded with the clamp-struts; I made a cardboard substitute of the main arm and rod. The rod and lower part of the arm form an isosceles triangle with corners measuring 65-65-50 degrees. The main arm is comprised of UFS-3 and -4 glued back-to-back. I thinned down (sanding) the backs to about half their thickness before gluing. Initially their length was about 5 cm. Sawed several angles topp and bottom.  A UFS-6 U-beam with one of the sides removed functioned as an L-piece which holds the chock block. The chock block IRL is adjustable by a nut-bolt (movable toward/away from hull). A 1.5mm thick triangle piece goes underneath the L-piece (Photo 17 (27XX)).

The chock block was made from plastic beam (3.5x4.5mm), shaped according to the IWM photos and correctly touching the submarine hull. Block was glued in the L-piece but with a circular spacer on its back. Eventually a rod with handle will mimic the adjustment bolt. Photo 18 (2721) shows the clamp-strut, the rod will be bend in the correct angle during final assembly.

The rod is 1.2mm diameter rod, glued in place in a small hole I drilled in the U-beam. Strictly speaking the rod is twice as thick as it should be for this scale, also in IRL the rod actually might be square and not round.
Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: s142 am 04 November 2018, 16:45:33
Hi Wulfing

Great work  top

Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: wulfing am 06 November 2018, 15:15:07
Hi everybody,
Many thanks for your comment Chris- s142.  I am glad you appreciate it.

Another small update showing you the clamp struts in place and the brackets installed.

Photo 19 (2724)
The rods of the clamps were bend and cut to size (about 19mm in length), and each assembly was glued while in their intended positions. Since I decided to make a static model of these clamps, I have to slide the submarine in and out for removal.

Photo 20 (2727)
The brackets were made from 3 and 2 mm diameter discs (0.5mm thick) and then cut to obtain a rectangular or triangular shape respectively, however retaining the round topp. Bolt heads will be glued on these brackets.
The H- and I-beams need to be cut to their correct length and then a bumper strip made from UFS-2 U-beam needs to be added (foreground). Again, I am not entirely sure where this bumper strip starts and ends, but the IWM photos give a pretty good idea.

Also visible is a wheel rim from the Bolddivision donor kit. Spare wheels and rims are often seen in photos of these trailers and I'll think about mounting one. Not visible are the laser cut wooden strips, also from the Bolddivision kit which will be used to fill the space between the keel and the keel support beam.
Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: wulfing am 13 November 2018, 16:07:24
Hi everybody,
This will be the last update of this build. Construction is finished; what is left to do is sanding, adding some details (bolt heads, adjustment nuts), and paint. I have settled for a dark yellow paint scheme, just like the Kaelble tractor, it should nicely off-set the otherwise gray diorama.

Photo 21 (2729) and Photo 22 (2730)
Last thing to add was the bumper strip mentioned earlier. A straightforward wrap around, starting and finishing at the highpoint where the main I-beams attach to the wheel frame, and hitting the support I-beams at the upper parts. Lastly I drilled out the holes in the drawbar and turntable assembly and inserted the bolts which connect them.

You see 8 wooden planks in the picture; these need to be cut to length and placed in/on the keel support beam to fill up the space between the beam and the submarines keel. But this will be done after painting.

This trailer is part of diorama depicting the Zuidersluis sea-lock in IJmuiden in 1945.
It is comprised of Verlinden Productions Seehund waterline and a Seehund on its trailer towed by CustomScale’s Kaelble Z6 G110 (see background). About a dozen figures will lively up the scene (Royal Model, VP, Alpine, U-models, Hornet heads). Inspiration for this diorama are the photos on page 108 in Mattes book Die Seehunde.

I hope you had as much fun seeing these posts as I had building this trailer.
Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: Mike2018 am 21 Dezember 2018, 19:54:06
Hey Wulfing,

sieht super aus  top

hast Du den mit Dergl zusammen entworfen und gebaut?

Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: wulfing am 21 Dezember 2018, 22:01:25
Hi Mike2018,
Vielen dank.
Nein, das war Zufall. Am selben tag, an dem er Bilder von seinem Design veröffentlichte,
habe ich Bilder der ersten Bauphase gepostet (7. Oktober).

Dergl hat die HMA Fotos verwendet und ein Italeri kit, ich habe eine Kombination daraus
gemacht von HMA & IWM und ein BoldDivision kit. Mit seinen Planzeichnungen können
Sie einen guten Anhänger bauen.

Titel: Re: Seehund Trailer Scale 1/35
Beitrag von: Dergl am 22 Dezember 2018, 06:15:23
Hallo Mike,

stimmt, was wulfing schreibt: war echt Zufall.
Ich hatte mich gerade entschieden meinem 127er statt einem Bootsständer den Trailer zu bauen, die Recherche begonnen und erste Skizzen gemacht. Da kam der 1/35er Beitrag, was mich sehr freute. Es gab keine Abstimmung oder Zusammenarbeit. Nur großes Interesse und Bewunderung meinerseits :-)