Watercat M12 (Jurmo Class) landing craft

Started by CB90

68 updates 240 likes 39 comments
CB90 #41 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

More filling and sanding.
Made boat unsinkable with some old foam in a can for the bow this will add strength and expanded polystyrene for the middle section .

The inverted chine come spray rail was sanded to size and filled at a 45 degree angle to the side. skins.

Regards Roy
Liked by jbkiwi and Colin H and
1 comment
  1. MotoPilot
    Chief Petty Officer 2nd Class
    Coming along nicely Roy. This looks like an interesting model.
    Have fun 🙂

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CB90 #42 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

Just started creating waterproof hatches, which will be taped down, and the cabin and its deck will be put on top in the future.🤞

Adding side foredecks only 1.75 ins wide as cargo area is wide, glued and weighted down.

Regards Roy
Liked by jbkiwi and Colin H

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CB90 #43 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

1.Tidy stern with 0.8mm cladding around wheel house area.

2. Add stringers to the deck for the start of foredeck construction, weights add pressure to the joints.

Regards Roy
Liked by jbkiwi and Colin H

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CB90 #44 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

Added port and starboard bump rail in 4mm walnut, along the top edge inline with the deck..

Fitted an Aluminium cover (3mm) for the exit ramp door at the Bow, doubled on the top edge to 6mm.

General removal of excess glue due to the nature of this Gorilla type glue which expands and foams as it dries, needs to be cut away with a Stanley type knife, (in-fact an 18mm break of knife)

Started on the Side fenders, never done this before to the side of a boat which will incorporate the bump rail.

Regards Roy
Liked by Colin H and jbkiwi

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CB90 #45 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

1. Side fenders completed, had great fun cleaning off excess glue.

2. Filling round Bow ramp, added hinges to ramp and front bump pads.

Regards Roy
Liked by stevedownunder and Colin H and
2 comments
  1. jbkiwi
    Fleet Admiral
    Getting there Roy,- did you think of making the bow door operate, or would sealing it have been a problem?

    JB
  2. CB90
    Captain
    Hi jbkiwi,

    Yes, sealing would be a problem. especially when she is slammed into reverse, assuming there is enough momentum and jet buckets don't break.

    But you could have a secondary seal behind the working door!
    I am considering having moving sliding doors on the cabin, with moving radar and lights. plus sound.

    Working door at start of this video below.

    see similar boat CB90 crash stop.

    I built a CB90 previously from scratch.
    (hence my handle CB90) by Docksta varvet of SWEDEN now produced by SAAB.

    https://model-boats.com/harbour/39713

    Regards Roy
    Liked by lindemann06 and peterd

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CB90 #46 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

1. Finishing of waterproof sub-decks hatches, these will be taped down when in operation.

2. Built couple of formers for the superstructures forward cabins.

3. Added 4 water pickups (two for motor water jackets and two for the ESCs.

4. Added to extra water outlets to the stern (ESCs).

5. Added bump strip to the stern.

Regards
Roy
Liked by jbkiwi and stevedownunder and
2 comments
  1. mturpin013Bronze
    Admiral
    Great work, one question will the water pickups have enough pressure to circulate the water as they are usually behind a prop forcing the water at considerable pressure, just a thought
  2. CB90
    Captain
    Hi mturpin013,

    I have noted from other water jet videos, that the water pressure wasted from the waterjet cooling is surprisingly high.

    (I can't find the video but some guy tried run a jet boat without the cooling pipe connected, it was facing sideways and he could not steer it due to the force of the water escaping from the outlet.)

    So I though I would try a low pressure scoop system, thus 4 pickups, if it doesn't work I will add a pump or revert to the jet cooling output, currently sealed with silicon rubber.

    Thanks for the feedback

    Regards Roy
    Liked by Colin H

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CB90 #47 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

1. Added strings for the forward cargo area.
2. Added strings for the Mid section cargo area.
3. Added skins to the sides.
4. Filled in stern corner sections of bump strip, still need shaping.
5. Added imitation doors to rear cargo area.
Note, some versions have no doors. just an open area across the section. but the last picture shows that some do have doors fitted.

Thanks to mturpin013 ( Vice Admiral) for questioning my water pickups, not possibly having enough pressure to circulate the water, as a precaution I have put a scoop under the hull, hope it will improve the chances of it working.

Regards Roy
Liked by jbkiwi and Colin H and

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CB90 #48 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,

The Shed is freezing, dare not put on heating, as the costs are high.
1. Added two more skins to the sides of the bow forward compartment.
2. Reinforced roof of mid section compartment.

ESC's have arrived about £18 each,
I have given up trying to order ECSs via Amazon's Chinese suppliers as they take your money and don't track the parcel deliberately, then 6 weeks when it has not arrived they give you a refund, no questions asked, this is because, they never had it and never sent it, all they do is waste your time, hoping that you forget to ask for a refund, and hold your money for 6 weeks in their bank account, a clever scheme.
Amazon I don't seem to be awear if it or cannot be bothered.

So now use a company called 'Wish' for chinese goods

120A ESC not really waterproof just hope the boat does not sink.
Compatible with sensor less brushless motors. Light weight, also brought programming card.

Regards Roy⛵
Liked by pressonreguardless and jbkiwi and

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CB90 #49 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates,
1. Picture of esc and its associated controller.
2 and 3. Fill bow section of forward cargo area with polystyrene.
4. Add roof to forward cargo area.
5. Basic clean up of forward cargo area.

I was going to put lights in the main cargo area as it has windows, but the 3mm black acrylic sheet I got for the job is completly light proof, so no point in putting in LEDs unless I buy something else for the windows!

Regards Roy
Liked by RNinMunich and jbkiwi and
2 comments
  1. stevedownunder
    Commodore
    Nice progress CB90,

    Pity about the Black acrylic, if you get some clear acrylic then paint the inside with Tamiya Smoke out of their clear range of paints, preferably sprayed, you can produce the desired tint.

    Cheers,
    Stephen.
    Liked by RNinMunich and pressonreguardless and
  2. CB90
    Captain
    Thanks stevedownunder,
    I have infact just brought some clear 2mm Perspex A4 and have been working on an idea to use LED lighting inside and a image.
    Regards Roy
    Liked by RNinMunich and Colin H

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CB90 #50 of 69

Watercat M12 (Jurmo Class) landing craft

Hi Shipmates
1. Cut out windows x 10.
2. Made light boxs x2 for windows and painted white.
3. Added 4 plates for lifting points.
4. Packed main cargo area with polystyrene.
5. Added two lights to door area.

Regards Roy
Liked by RNinMunich and jbkiwi and

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