-  The original AHTI


The AHTI was built in 2002 at the spanish shipyard Astilleros Armon. She has a sister called UKKO. Both newbuilds are for Fortum Oil and were designed by Beacon Ltd. Fortum need these tugboats to assist her crude oil tankers in the ports along the south coast of Finnland. About 5 month of the year they have ice around and so they use the tugs as ice breakers when needed. Both tugs have a huge bowwinch fitted with dyneemarope from Karmoy to assist berthing the tankers and the low towing point provides the best performance and minimizing the risk of capsize. For long distance towing both tugs have a stern winch from the same manufacturer. The stern winch carries a steelwire. Next to the stern winch is fitted a Mampaey-Towing-hook. For the handling of the work boat and the towing wire a big Palfinger Marine crane was fitted. The government of Finnland bought special oil recovering equipment containers. For these containers the tugboats have fixing points on the aft deck.
The AHTI is powered by a pair of Wärtsilä diesel engines, each developing 2500kW. The engines powering Rolls-Royce Aquamaster 3001CP azimuth thruster. The nozzled controllable pitch propellers have a diameter of 3m. The generator sets are Volvo driven units each producing 120kW. On trials the AHTI achieved a bollard pull of 70 tonne (70.000kg) ahead. Both tugboats have a length of 33,5m and a beam of 12,8m


-   the building of the model

On my first visit I had to decide which tug I was going to build. My friend Jarkko made the decision for me because he invited me to stay a week onboard the AHTI and I had the chance to take lots of photos and print all the plans for making the model. I started by building the superstructure. Like all my other models I built the superstructure from electronic circuit plates 0.5 mm thick. I dont like to see the joints so I had to solder the plates from the inside just after soldering the super structure together I fitted the brass tubes for the self drenching system. The hull frames I made of multiplex. I planked these frames and covered them with fibreglass matting and resin the hull consist of 10 KG filler, 24 Sq meter of 80 G fiberglass mat and 4 Sq meter of 160 fiberglass matting after sanding and priming I seperated the hull from the mould I trimmed the hull to the deck line and fitted strengtheners inside to the deckline to suport the deck and give strenght to where it is most needed.
In Germany you can`t buy azimuth thruster scale of 1:20. So I had to built them myself. I bought two elbow fittings in a plumbers shop and fitted the bevel gears inside. The AHTI is powered by two Elefant electric motors of Conrad Electronics. The steering is provided by 4x 24kg servos from the same shop.
All the windows in the deckhouse are cut by hand using a proxxon fitted with a burr. In the side of the deckhouse you will find some air grilles. Behind these grilles I fitted computer cooling fans for cooling the electronics below main deck. The grilles are costructed in a special way. It is very difficult to glue the slats of the grille in the exact position. So I bought plates of stairs in scale 1:200 and glued on every step a small strip of aluminium plate. If I need a grille with a fan behind I cut a hole in the stairplates and glue the strips on it. For all the air grilles I build real working Cover doors. They are made of thin brass plates and the hinges are working like the real ones.

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Ahti frontview on the bridge
frames a special bathtub
thruster in parts thruster with nozzle
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After finishing the air grilles I constructed the railings. All the stancions of the railings are made of a right-angled brass profile. Two round brass wires go through every stancion. On the top of each stancion I soldered the handrail. It is not a easy job as you have to bend two identical profiles. Next the mast, I had a plan of the mast but if you compare the plan with the photos you will see there are lots of differences. So I took the main sizes from the plan and the details from the photos. The base of the mast is made of brass tube with a diameter of 12mm.where two sections meet I cut small slits in the tubes ends and soldered a small strip inside. Making the joint stronger. The plattform of the mast is made of circuit plates. this platform has the the same kind of railing as on the deckshouse. The ladder has right-angled steps. After soldering the steps I fitted the safety cages around the ladder. then I soldered the yardarms in the right places. I did not solder the mast in its place because it will complicate the further fitting out of the deckshouse. When the mast is fitted and painted I will fit the cables for lights. In the meantime I fitted the self-drenging system. I made this from small brass tubes. It is very difficlt to bend tubes. If you are not carefull the tube will fold. To bend the material in a safe way you must heat the material with a blow lamp and cool it to soften the brass Then you fill the tube with a very fine sand and close both ends of the tube. than you can bend it. But be carefull not every radius is possible. For small diameters, up to 3mm, you can use a "bending machine". You can buy this at Conrad Electronics (Germany) The tubes were fitted with small pipe clamps to deckshouse. These clamps are also made of brass plates. I bend a small strip around the tube and solder a small wire as the support. The flanges for the FiFi-tubes are made of round profile with a diameter of 6mm. I drilled a hole in the profile and cut it in small discs. Then I drilled small holes to fit the imitation bolts. Now I push the flanges on the tube and glue them in the right position. On the starbord side of the deckhouse there is a box for the emergency accumulator. I constructed this box with real working hinges. Every hinge consists of five parts. behind this box there is the framework to protect the air condition against damage.

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strengthening in the hull hull with superstructure
flanges FiFi tubes
bridge deckhouse from starbord side
bulwark at portside bulwark at starbordside
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For the construction of the hatches on deck I used circuit plates. These plates are 1.5mm thick. The cover is made of brass plates. To build these covers I cut a piece of plate, I then bend the edges with a small pair of pliers. The next step is to make small cuts in the covers. In these cuts I solder small strips of brass plates to build the hinges. To hold these covers closed you need a latch. These latches consists of small screws from an optician. I soldered a small grip to the nut and fitted the screw in the hatch. Now I have my own model latch. The small screws at the opticians are much cheaper than in model shops. For the bulwark I cut templates from cardboard. Then I copied the lines on to brass plate. I soldered the bulwarks directly to the deck. The upper edge of the bulwark are made of a tube with a diameter of 6mm. The last work on the bulwark was to fit the bulwark stachions. From outside I soldered the fendering to the bulwark. Now it was time to make the first waterline test. I loaded several batteries, stones and 10 bottles filled with water in the hull, but I was more than six centimeters short of the waterline..

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engineroom hatch test swimming
bulwark at the stern stern fendering
ASD-remote control steering mechanism
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I then fitted the ventilation covers over the grilles.but the covers proved to be to tight for easy opening so not only did I have to reconstruct the covers and hinges because the hinges were to rough. Now I can open these covers very easy. On the real AHTI the air grilles are fitted with screws and nuts to the deckshouse side. I imitate the screws with small pieces of brass wire.
Inside the hull I fitted two water-tight compartments for ballasting the model. To flood the compartments I cut small slits in the hull. With some pumps I fill and bail these tanks

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funnel starbordside funnel portside
fans superstructure from starbordside
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I ordered a pair of model figures to test the size of every piece on deck of my AHTI. Now I discovered that the distance between the railings and the deckhouse roof was too small. I removed the railing and I increased the distance to about 7mm. It is very good to buy a scale figure. It doesn´t matter what kind of figure it is. You can test your construction with a knight or with an indian. On both sides of the bridge there are small platform steps. On the steps railing attachments for the life bouys are fitted. The parts and the rescue davit are hard soldered. The ladder from the aft deck to deckhouse roof is made of brassplate strips, the front end of these strips are bent and the steps are made from a splash guard. Some months ago I turned the drums for the bow and sternwinch. The gearbox was made of circuit plates and for the axle I drilled a hole with a diameter of 8mm in it. The bowwinch has two bridge bearings. In every bridge bearing there is a bearing for the axle. For all three drums I built brakes from small stripes of brass plate. I cut the strips in pieces and put these pieces together with a special selfmade hinge. The brakebands have a brake lever. When you apply this lever the drum is locked. The bowwinch has a special framework to support a cover. This cover is to protect the winch against freezing spray in winter times. The build up of ice on the winch could cause a lot of trouble. I constructed the framework of 2mm brass tubes. I soldered the tubes and fitted the framework with screws to the winch.

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stairs to the aftdeck life buoy on portside
store bow-bollard
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For the motors of the winch I made a casting mould and casted all the needed parts with Polymethylmethacrylat (PMMA). I glued the motors into position. In front of the winch a huge bow bollard is located. This bollard was made of coppertubes and soldered to the deck. The pods of the thrusters were made of elbow fittings ( see earlier ). But the diameter of these fitting was to small so I built a facing. The facing is made of fibreglass mat. This facing was glued with silicon glue into position, so it is easier to remove for repairs. In Addition to that I built a lot of other parts e.g. H-bollards, funneltubes and gutters. After this work I started building the oil pressure tubes at the bowwinch and the sternwinch. Unfortunately the plans I have don`t show the size and the run of all the tubes. So I had to use the photos. The tubes are made of brass wire and the fittings are made of polystyrol. . It was a lot of work to bent all the brass wires and solder them in the right position. Most of the tubes have tubes as a connetion. I built these tube from heat shrink tube. I put a brass wire with the needed diameter inside the tubes and heat it. Than I removed the wire and fitted the tubes into the right position. I built two brakes for the bowwinch. The brakes are screwed on the lock for the anchor chains. To built these brake I cut two discs from curcuit plates and soldered a small brass stripe around. The warping head is made of brass. Now only the brake band is missing.
The Ahti has a Palfinger Marine crane just beside to the stern winch. I got some drawings of the crane from Palfinger. Like most of the parts I built the crane by using brass plates. I cut out all the parts and soldered these parts together.

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bow fendering bow view
bow winch starbordside bow winch portside
starbord view to bow stern view of deckshouse
topview of the winch thrusters with facing
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After this work I started building the oil pressure tubes at the bowwinch and the sternwinch. Unfortunately the plans I have don`t show the size and the run of all the tubes. So I had to use the photos. The tubes are made of brass wire and the fittings are made of polystyrol. It was a lot of work to bent all the brass wires and solder them in the right position. Most of the tubes have tubes as a connetion. I built these tube from heat shrink tube. I put a brass wire with the needed diameter inside the tubes and heat it. Than I removed the wire and fitted the tubes into the right position. I built two brakes for the bowwinch. The brakes are screwed on the lock for the anchor chains. To built these brake I cut two discs from curcuit plates and soldered a small brass stripe around. The warping head is made of brass. Now only the brake band is missing.
The Ahti has a Palfinger Marine crane just beside to the stern winch. I got some drawings of the crane from Palfinger. Like most of the parts I built the crane by using brass plates. I cut out all the parts and soldered these parts together. The cran has his base on the starbord side of the winch. The towing hook is fitted to this base. The chassis of the towing hook is also made of circuit plates. Due to the high weight of the crane it will not be radiocontroled. I have to use a hydraulic system and I can´t afford this. Just after the stern winch a spooling gear is fitted. I built this gear from different part of brass tubes, circuit plates and stainless steel round bar to avoid rusting.
I stopped work nearly one year ago because of the birth of my son. Now I found the time to continuing the building of the Ahti. It was time to fit the steering gear of the thurster in the hull. I built these gears 1,5 years ago, but I didn´t find the time to fix them. Now only the electric motors are missing. Than I will have the first testsail with my model.

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bow winch model bow winch original
stern winch model stern winch original
prepared for test swimming test of water tanks
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The crane onboard of the AHTI is a knuckle boom crane manufactured by Palfinger. It is located on the starbord side behind the deckshouse right next to the stern winch. The whole model was made of brass and the extension are working. The lift cylinders are made of brass tubes and all pressure pipes are made of thin brass wire. Due to the high weight of the crane it is only movable by a oil hydraulic. But it is too expensive for me. At the basement of the crane you will find the towing hook. It is made of circuit board and brass. Amidship behind the sternwinch I fitted the spooling gear. The bars for the slider are made of stainless steel. The sliders was made of a collection of different kind of brass tubes and plates. All the exhausters behind the bulwark were made of PS and thin alu plate.

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crane folded crane fitted on deck
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After the birth of my son I had to evacuate my hobby room and converted it into a childrens room. While this the model of the Ahti was stored into the barn. After I realised that I will not have the time and the room to finish her as a working model, I offered the model at my website. In spring 2010 I got the inquiry to finish her a static ( display ) model. The guy from swedens wants to show her in a maritime permanent exhibition in a castle near Stockholm. I finished the model in june and a big truck carried her to sweden. Attached you will find some photos of the building process and of the finished model.

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forecastledeck superstructure portside
rearside superstructure crane
topview aftdeck bow winch
side view transport box
bow view detail bow winch
detail radar detail bow winch
detail bow winch akkubox and AC-unit starbord side
rear access bridge side deck port side
MOB-Station topview bow winch
starbord side thrusters
detail stern winch detail exhauster
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