1/24 Scale Clyde Class Lifeboat

[Tiny69]

My next build is to be a Clyde Class Lifeboat at 1:24 scale. Only three of the Clyde Class where ever built with the first two only having some slight differences whilst the third had a completely different superstructure similair to that of the Arun Class. The vessels were 70ft long, the longest used by the RNLI, which will make the model 35 inches long. (890mm)

Breif History
Following visits by the RNLI's managers to the Netherlands and Germany which had successfully employed cruising lifeboats it was decided tosanction and build two permanently manned RNLI vessels. The two boats went on trail in 1966 and in 1968 went on station with 70-001 stationed at Clovelly and 70-002 at Kirkwall. 70-003 was built some years later as a relief boat for the other two.

All three were is service with the RNLI until 1988 when they were sold on. 70-001 is in private owner ship currently in the Netherlands. 70-002 went to Reyjavik as part of the Icelandic Lifeboat Service before also being sold on into private ownership. 70-003 was sold on, modified and became the Gemini Explorer giving pleasure trips dolphin watching on the Moray Firth.

The model as mentioned will be 35 inches long with twin electric motors. I have obtained a GA drawing from the RNLI and Section drawings from a fellow modeller who was kind enough to send me a copy of the set they had. I will be drawing my own set on the PC

[Tiny69]

To get this project started a set of plans were purchased from the RNLI consisting of a sheet with the plan and a sheet showing the profile. The are very detailed showing all the internal detail of the superstructure and hull drawn at 1/2 inch = 1 foot. The down side to these drawings is there are only three cross sections which I feel is not enough to build an accurate hull.

Sheet 1 - Plan

Sheet 2 - Profile

A drawing showing more hull sections was required and I was fortunate to receive a set of hull lines from a fellow modeller which are drawn at 1 inch = 1 foot.

Sheet 3 - Hull Lines

With this set of drawings I now spent some time studying them to work out the best way to approach building a fully sailing model.

[Tiny69]

Whilst studying the very detailed drawings I came to the conclusion that I would need to draw a simplified set to work from that would clearly show the main elements of the vessel. Firstly a trip to the reprographics shop was required to have the paper copies scanned into an electronic format to be used in the AutoCAD program I use to draw all my drawings. The scanned image is simply traced over using the CAD program but there is quite a bit of setting up to do before any drawing can take place. The first step is to set up a number of layers, think of these as sheets of tracing paper laid on top of each, one of which the scanned images of the plan is placed on and locked. The other layers are used to draw over the plans such as outlines, centre lines and hidden lines. The next step the hull lines image was placed onto the layer and scaled to the size required, which in this case is a hull length of 902mm. Next the image was rotated to ensure all the vertical lines were square making it easier to trace over. Now I could start the lengthy task of drawing out the hull and frame sections.

With the hull lines completed I decided that I would start to copy the plan and profile views of the lifeboat. The setting up procedure was repeated with the image of the deck and profile views, ensuring they were both correctly scaled and lined up before I started to draw them out. All this may seem like a lengthy process but I find it a useful way of understanding how all the elements of a ship fit together and how I am going to construct the model. The attached images show the drawing in production with the scanned image in the background and the blue lines are what I have drawn over the top.

[Tiny69]

With the basic hull lines and rib outlines complete I started to draw out each of the individual ribs. First a centre line was drawn and the half rib shape copied to line up with the centre line. The rib line was then mirrored to form the other side and to complete the shape an arc was drawn on top to give the profile of the deck. To allow for the thickness of the outside planking and deck the lines were offset by 1mm. To finish off the internal cut out was drawn.

After drawing all the ribs out the next step was to draw out the keel shape with the rib positions. Now I was able to work out all the interlocking cut outs for the ribs to fit into the keel and the position of the motors. I also determined the locations of the two prop shaft and drew the two holes they would pass through in rib No.6 and 7.

With the keel and ribs complete they were all laid out, including a keel building base at the correct angle to the ribs would be vertical during construction, a separate file was saved and sent to SLEC UK to get a quote for cutting out using a CNC router. I emailed the file to them with a request for a quote and within a couple of days I received a quotation for the keel and ribs to be cut out of 3mm birch plywood. After some discussions and corrections to the artwork so the router machine could understand the cutting patterns they were able to proceed with the job.

[Tiny69]

It was a couple of weeks after the order was placed that I received a large parcel containing three sheets of 3mm thick plywood, two of which contained the sections and keel cut to shape.

The first sheet has the keel and the bow and stern ribs. At the bottom is the building keel I will use to mount the keel on so the ribs will be vertical in relation to the building base.

The second sheet contains the midship ribs.

This photo shows the lime sheet for skinning the hull and balsa wood block for the bow and stern sections. Also shown are the two RS385 motors that will be installed later.

[Tiny69]

Time to start building the hull but first a base to build it on is required. I had some 18mm thick plywood sheet leftover from a DIY project so measured out a piece 1000 x 300mm and cut it out with a hand saw. Down the middle a pencil centreline was then made as a reference for mounting the building keel.

To ensure the building keel will be square to the base I cut four rectangular pieces of wood to support the ends of the building keel on the mini table top circular saw checking they were true with an engineering square. Now I could glue the building keel in place along the centreline of the base board using some rapid drying wood glue, again checking everything was square.

With the two ends supported the next step was to cut more square rectangular pieces of ply and glue then at intervals to support the full length of the building keel.

[Tiny69]

The building keel was now almost ready for the keel to be mounted, but first fourteen blocks had to be cut and glued either side ensuring they were positioned not to interfere with the installation of the ribs later. The keel could now be slotted down onto the building keel and the installation of the ribs could be started.

Starting with ribs four and five each one were slotted in place both side of the motor mount and checked that they were perpendicular to the building base with the engineering square. Once happy with the fitment they were removed, glued in place and checked again.

Moving out from the centre each of the remaining ribs were fitted, checked and then glued in position.

[Tiny69]

The next stage of the build was to interlock the 3mm x 3mm wooden stringers between the ribs starting at the bow and running one down the centre to rib number three. Then either side two more were fitted marking the edge of the main superstructure. Around the outer edge of the ribs two stringers were glued in position forming the outside edge of the deck. Now all the ribs were securely held in place.

[Tiny69]

Continuing on with the hull I could now fit the rest of the stringers to the hull, a further three rows on each side, glued into the slots already cut out of the ribs. The skeleton of the hull was now complete ready for skinning.

[ModelMonkey]

[davidwaples]

Nice project. You're off to a great start. Looking forward to seeing this one come together.
Dave

[Tiny69]

To start skinning the hull first it had to be removed from the building frame and turned over. The building frame was removed from the base board and two new building frames made and glued to the base board. The skeleton could now be mounted ready for the work to start on the outside of the hull using 1mm thick limewood. Initially I was going to cut the sheet limewood into 10mm wide strips and plank over the frames but thought I would cut panels to the shapes of the frames and stringers instead. To obtain the shapes of the panels I used thin paper held in place over the hull and the natural daylight from behind shining through drew out the required shape on to the paper. This was then cut out and offered up to the hull to check it fit. Any trimming was done and the paper shape was placed on to limewood sheet and traced around. Using a sharp knife the panel was cut out, checked against the hull frames, trimmed before I was ready to start gluing them in place. Working from the bow to the stern, along the keel and on each side the individual panels were glued and clamped in place.

[Jaguar]

I love to see the first stages of any build. Very nice job.

I cannot wait to see new updates.

Jorge

[Aop Aur]

Very nice! Looking forward to more!

Aop

[gmctaggart]

Looking good.

Gord

[JIM BAUMANN]

most worthy subject!

great explanatory images too!-

JIM B

[Tiny69]

It has been some time since I have posted on this build but here is an update. I have been continuing on with the skinning of the hull with the limewood panels and have now completed them all. Looks like a patchwork quilt at the moment but it is something to work with. I have also cut the slots in the hull for the prop tubes to pass through which are quite long due to the angle of the tubes.

[JIM BAUMANN]

Good to see you back on the case!!

at this point the ship has a skin--and it starts to progress better!


JB

[Tiny69]

With the outer skin complete the next stage of the build is to line the inside of the hull with glass fibre matt and resin. I do this to strengthen the limewood skin to stop it flexing before I start to sand the hull to its final shape. I bought a resin kit from Halfords which contained 0.5sq metres of glass matt, 500ml of resin, hardener, mixing sticks, measuring cup and some disposable gloves. I cut the glass matt into strips and laid them between each of the ribs. I then poured out some resin into the measuring cup and added the hardener and mixed then thoroughly together. Working from the stern the mixed resin was then applied to the glass matt starting at the keel and work up the side of the hull. Using the mixing stick the resin was worked into the matt to ensure it was in contact with the outer skin of the hull and any air bubbles removed. The resin takes about ten minutes to start to go like jelly when it becomes unworkable, which was plenty of time to work it into the matt. Once happy with the density of the applied resin I moved onto the next compartment repeating the whole process until all the compartments were completed.

[DrPR]

Coating the inside of the hull is a good idea. The first couple of plank on frame hulls I built developed cracks between the planks after a year or two. The next hull I made was coated on the inside and 20 years later it still is smooth with no cracks.

However, I didn't use the fiberglass cloth. I used a thin two-part epoxy paint that model airplane builders used to fuel-proof balsa. Because it was a paint it was very easy to apply with a brush - I laid it on very thick. It soaked into the basswood planks and glued them together firmly. There is a thin layer of the epoxy over the entire inner surface of the hull that gives it added strength.

Phil