Hawkins Class Hull Project

Discussion in 'Warship Builds' started by Bob Pottle, Jun 24, 2018.

  1. Bob Pottle

    Bob Pottle Well-Known Member

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    Several years ago I bought Profile Morskie 1/144 plans for HMS Frobisher, one of the post-WWI British Hawkins Class heavy cruisers. The plan was to build a hull mold for Strike Models; Stephen Mogret and I thought the Class had potential as a combat model with a low placed pair of single BB cannons aft that could be trained up to 15 degrees to port and starboard.

    For various reasons the project never got off the ground, but having just refitted SNS Canarias my interest in the hobby has been renewed and I've decided to make the Hawkins Class hull mold this summer. This will be my first new hull project since the Profintern/Krasni Krim light cruiser plug I donated to Strike Models 4 years ago.

    These were fairly large cruisers with a displacement nearly that of the later County Class, a beam of 65' and loa of 605'. The bulged hulls were based on the hull design of battlecruiser HMS Furious. Armament was initially 7 x 7.5" guns in shields, 2 forward, 2 amidships port and starboard, and 3 astern with 2 in line on the quarterdeck, which will be 1.25" above the waterline in 1/144 scale.

    One ship, Raleigh, was lost on a reef in Labrador very early in its career. The other 4 ships appeared in a variety of forms, including some that could be used in non-combat roles.

    Cavendish was completed in 1918 as a small experimental aircraft carrier with flight deck aft, then back to cruiser configuration but retaining the seaplane hangar and crane in front of the bridge and having 1 less main gun. It was renamed Vindictive, disarmed under the Washington treaty and converted to a cadet training ship with a couple of light guns. In WWII it served as a fleet repair ship, so could be used in IRCWCC competition as a convoy ship in either of those roles.

    Frobisher was also converted to a training ship but retained 5 of its main guns for a few years before all the 7.5" guns were removed and placed in storage. Effingham and Hawkins were disarmed and placed in reserve, then rearmed for WWII. Just before the war Effingham was converted to a main armament of 9 x 6" guns; the plan was to re-equip Hawkins and Frobisher with 6" guns but the start of WWII prevented that.

    Here are some photos of Argonaut 1/1250 models of the Hawkins Class in different configurations, all of which could be built from the hull:

    1) HMS Vindictive as a cadet training ship just before WWII. It had a pair of 4.7" guns forward, on and in front of the seaplane hangar from when it was completed as a small carrier in 1918. I think the configuration remained the same when it was a repair and depot ship in WWII. It was slow, having had half the machinery and a funnel removed when converted to a training ship. It would make an interesting convoy ship for Campaign Lite.

    IMG_3158.JPG

    2) HMS Frobisher as a cadet training ship pre-WWII with a catapult and crane in the former positions of #5 and #6 guns. In WWII #5 and #6 guns were reinstalled but #3 and #4 amidships were omitted to make room for a heavier AA armament. The large deck house under the mainmast was removed too. The plans I have are for Frobisher in 1942.

    IMG_3161.JPG

    3) HMS Hawkins with full armament as built and as carried in WWII. Note positions of the 2 quarterdeck guns. A 10 degree angle outward will allow #6 gun to clear the small deck house just aft of it. The crew shelter just ahead of #7 gun will help conceal the upfeed tube to a BB cannon in #7 position. Looks similar to Frobisher in WWII but had 7 instead of 5 x 7.5" guns and a lighter AA armament.

    IMG_3162.JPG

    4) HMS Effingham after conversion to 9 x 6" guns and a trunked funnel just before WWII. This is the version I like best but the 6" gun shields are so small the stern cannons will have to go in the small superstructure at the forward end of the q-deck under #7 gun. With 6" guns she's a 3.0 unit CL rather than a CA and is faster than models of her sisterships.

    IMG_3163.JPG
     
    Last edited: Sep 5, 2018
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  2. Bob Pottle

    Bob Pottle Well-Known Member

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    This evening I took a close look at the Profile Morskie 1/144 scale plans for HMS Frobisher (1942) for the first time since buying them at least 3 years ago. I did some calculations for how wide and long the drawings should be for 1/144 and was amazed to find the plan is exactly 1/144 scale. Quite impressive.

    The plans are very nicely done and highly detailed. It's easy to see that the bulged Kent Class heavy cruiser hull design was a development of the Hawkins Class hull. The cross-sections are nearly identical with the exceptions that the low quarterdeck is much longer than the cut-down q-decks on Suffolk and Cumberland and that there's no bow 'knuckle'. The bow has a pronounced flare like battlecruiser HMS Furious, from which the Hawkins Class hull shape was derived. (The flare is much more prominent than on the 1/1250 scale models.) The Hawkins Class beam is 1/4" narrower than the Kents in 1/144 (65' vs 68') and ~2" shorter (605' vs 630').

    From above the hull outline is very similar to the Kent Class and later 'County' subgroups (London and Dorsetshire Classes). Hull depth from forecastle deck amidships to keel is 3 3/8" versus 3 3/4" for the Kent Class. Standard displacement draft for the Hawkins Class is 1/4" less than the Kent's and freeboard above that is 1/8" less, so overall a quite similar but marginally smaller hull (4% smaller in both beam and loa). Prop shaft and rudder locations are essentially identical to the Kent Class.

    Having made the Kent/Canarias Class hull plug and mold in 1997 (later sold to Strike) this will almost be a repeat. I'm off to the professional photocopier tomorrow to have set of accurate hull cross sections, side and top views printed and will start the hull plug while on vacation in 2 weeks.

    I'll follow up with the London and Dorsetshire Class hull mold in the fall. I have a beautiful set of Taubmann plans for Dorsetshire as built. Those Counties will be easier to sheet because they don't have a bulge (and the plug will be easier to make).
     
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  3. Bob Pottle

    Bob Pottle Well-Known Member

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    I got the photocopies of the side view and cross-sections yesterday. They'll be glued to 1/4" basswood and the hull frame parts will be cut out. The hold up today is that no one seems to sell rubber cement anymore; it's the best way to glue the photocopies to the wood.
     
  4. djranier

    djranier Well-Known Member

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    No Weldwood? How dare they.
     
  5. Bob Pottle

    Bob Pottle Well-Known Member

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    I've never seen Weldwood for sale in Halifax. I'll be in a major hardware store in another province later today (getting more materials for post-flood cottage repairs) - maybe it'll be sold there.
     
  6. Bob Pottle

    Bob Pottle Well-Known Member

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    No Weldwood found at stores in Nova Scotia or New Brunswick. Lots of other 'Weld' products but no one had heard of Weldwood.

    I'll have to find a store with Elmer's rubber cement. One more art supply store to check. I'd like to get the cross sections glued to the basswood and cut them out while on vacation next week.
     
  7. SteveT44

    SteveT44 Well-Known Member

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    You may have to try your Canadian version of contact cement. In stock at your local Rona store.

    https://www.rona.ca/en/contact-cement-01805113--1
     
  8. Mad_Modeller

    Mad_Modeller Active Member

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  9. Bob Pottle

    Bob Pottle Well-Known Member

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    The large art supply store in downtown Halifax has rubber cement but the traffic and parking situation is always bad. I'll take trip to the local Michael's instead.
    Thanks Steve, that's the same stuff I used to attach the sheet styrene outer sides to CVL Ibuki's inner fiberglass hangar walls - see Ibuki build thread. (I used styrene for the outer layer to make building and attaching styrene AA gun positions and galleries easier. )

    There's a Lepages solvent for removing the contact cement, which would make hull cleanup for resheeting easy.
     
  10. Bob Pottle

    Bob Pottle Well-Known Member

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    The 16 hull cross-sections for the Hawkins Class plug have been cut out and are being glued to 1/8" basswood. I hope to have the hull framework completed in 2-3 weeks. The similarity to the HMS Furious battlecruiser hull, from which the Hawkins hull design was derived, is clear in the bulge shape and the very prominent bow flare.
     
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  11. Bob Pottle

    Bob Pottle Well-Known Member

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    My late grandfather's 50+ year old Mastercraft scroll saw failed yesterday with a seized motor as I was cutting out the 11th hull frame. Hopefully I can find a new saw this morning and get the rest of the parts cut out and assembled today.


    The forecastle deck hull frames are a perfect match in height to the hull profile but strangely the quarterdeck sections are all 1-2 mm high and need their top edges trimmed.

    IMG_3185.JPG


    Forward hull frames and hull profile. The hull has a prominent bow flare. Those who've bought Courageous or Furious hulls from me or from Strike Models will recognize the similarity in the hull shapes. All were designed by RN WWI architect H. D'Eyncourt (designer of Hood too), with the Hawkins hull being a scaled down version of Furious.

    IMG_3186.JPG


    Aft profile and frames. The rudder is HMS Cumberland''s and projects 1/8" below the keel because Cumberland's stern isn't as deep. Effingham's rudder will be an identical conversion of a Robbe rudder kit.

    IMG_3187.JPG


    Late 1950s or early 1960s Mastercraft scroll saw after motor failure. Since the late 1960s the saw has been used to make all of my model ships, boats, submarines and RC combat hull plugs.

    IMG_3188.JPG


    HMS Cumberland hull for size comparison. The Kent Class was 25' (~2") longer than the Hawkins Class and the hull was slightly deeper (3/8") from forecastle deck to keel. The bow shapes were quite different and the bulges on the Hawkins were shorter, so the bulge stringers won't go as far aft, ending about 2 windows further forward. Cumberland's stern guns in Y turret will be at forecastle deck level, but the 2 single aft guns on the Effingham will be much lower. Trained out 15 degrees #7 gun's 5" long barrel will project more than 1" over the side of the quarterdeck close to the stern (the gun location is at #14 frame) and will be about 1.25" above water level. #6 gun is further forward (between frames 11 and 12) and further from the deck edge so it's barrel can't be depressed as far.

    IMG_3189.JPG
     
    Last edited: Jul 22, 2018
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  12. Bob Pottle

    Bob Pottle Well-Known Member

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    I bought a new scroll saw today and finished cutting out the components of the wooden hull plug frame. They fit together well in their slots and at right angles to each other. A few need 1-2mm height adjustments and all edges need sanding before the framework is glued together this weekend.


    IMG_3190.JPG



    IMG_3191.JPG



    IMG_3192.JPG



    The Kent and Hawkins Class hulls are similar; both were designed by D'Eyncourt with their sides sloping inward at 10 degrees until they met the bulges (also a feature of his HMS Hood design).

    IMG_3194.JPG
     
    Last edited: Jul 20, 2018
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  13. Anvil_x

    Anvil_x Well-Known Member

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    so... I'll let my inexperience show. How are you going to get the fiberglass hull off of the plug with those bulges? will you do it in two halves divided longitudinally and then glass them together?
     
  14. Bob Pottle

    Bob Pottle Well-Known Member

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    All of the 15+ molds I've made except for the small Siamese 'pocket heavy cruiser' Sri Ayuthia have been 2 part molds and most have been bulged or bulbous (I-400, Albatross, Erebus/Terror, Roberts/Abercrombie, Gorgon, Canarias, Kent, Courageous, Furious and Hood). Other hulls had casemates or armour belts so also needed 2 piece molds (Espana, Black Prince, Profintern, Vanguard). All of those molds except Albatross and Erebus/Terror ended up with Strike Models. Battlers Connection got my Z24 hull mold.

    After the hull plug is finished it's painted and a wide piece of flexible stryene or thin plywood is screwed to the top to form a flange for molding. The hull is turned over and a vertical wooden flange 2-3" high is made to follow the center of the keel, bow and stern and temporarily attached with silicone sealant on one side. The other side of the flange and half of the upside down plug and deck flange are waxed and polished multiple times with mold release wax.

    After a day to allow off-gassing from the wax a thick layer of gelcoat is painted onto the waxed half of the hull and its flanges. After another day a layer of fiberglass is added, at least 1/8" thick. After that has cured for a couple of days the wooden keel flange is removed, exposing a fiberglass flange. That flange and the other half of the hull and its deck flange are waxed and the process is repeated to make the second half of the mold.

    Wax prevents the second half of the hull mold and it's fiberglass keel flange from sticking to the first fiberglass keel flange. When the second half has cured holes are drilled through both keel flanges for the bolts that will later hold the halves of the mold together in proper allignment. Then plastic wedges are driven between the keel flanges. If all went well the 2 halves of the finished hull mold will pop off the hull plug. After much waxing the hull mold is ready for use.

    When a hull has been laid up in the mold and has cured the flange bolts are removed and the 2 halves of the mold are removed from the hull.
     
    Last edited: Jul 20, 2018
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  15. Kevin P.

    Kevin P. Well-Known Member

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    Very nice bob, what brand of foam do you use to fill it in?
     
  16. Bob Pottle

    Bob Pottle Well-Known Member

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    I use expanding spray foam for insulating. Solid foam dissolves if it contacts resin or gelcoat, which can happen if the drywall compound is applied too thinly. WIth the spray foam care has to be taken to not inject too much - it can distort the wooden frame. As the build proceeds you'll see reinforcements added to the frame to reduce flexing.
     
  17. Kevin P.

    Kevin P. Well-Known Member

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    Do you ever have issues with the foam swelling/shrinking after you sand it down? I used spray foam on one plug and once I was close to finished the foam swelled a bit (maybe from humidity) so the plug started looking like the Michelin Man.
     
  18. Anvil_x

    Anvil_x Well-Known Member

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    Thanks for the description, Bob. when you get to that stage, would you mind posting pics please?
     
  19. Bob Pottle

    Bob Pottle Well-Known Member

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    Yes, that's happened a few times but only in small areas. I cut out the area and filled it with drywall compound. I wonder if it's due to applying plaster or drywall compound too soon. I wait a couple of days after carving the foam before drywalling it.
     
    Last edited: Aug 20, 2018
  20. Bob Pottle

    Bob Pottle Well-Known Member

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    More photos will be posted throughout the build.

    Today the 3 sections of the wooden hull framework have been glued together and supports for the 1/32" basswood deck are being installed between the frames.
     
    Last edited: Jul 22, 2018