PTF England

Yacht Conversion

(email received 07-14-2013)

Hi Dan,

          Good to hear back from you. It's always nice to happen across people who appreciate such fine vessels such as the Nasty Class. In terms of design and construction, they were fantastic vessels and sadly boats of that caliber aren't built anymore. 

We bought her back in 1986 in the United Kingdom. There were 3 Nasty Class vessels for sale. One has been converted into a houseboat, one was dry docked for a lengthy period to dry the hull and apply a fibre glass coating over the wood (West System) before being shipped to Australia and the other one is ours. Over the years, I've actually seen the two other hulls in person on the English South Coast. Our vessel was P347 'LOM' built by Westermoen in Norway for the Royal Norwegian Navy. There is one reference to the vessel on the link you sent me. [ - Dan] Ours is the one installed with the GM/Detroit Diesel 8V71's (that apparently do not give much performance). 

We were totally new to boating at the time, so we enlisted the help of a naval architect to design and supervise the conversion not for it to end up too 'boxy' like some other owner managed conversions we had seen along the way. 

We had the option to keep the original Napier Deltic engines. As wonderful as it sounded to have a 27 meter yacht capable of those speeds, we ruled them out on grounds of practicality. The vessel was intended to be motored down to the Mediterranean and even though the Deltic's were a tremendous piece of machinery, we imagined there would also be a tremendous cost attached if anything went wrong as well as finding anyone in that region who specialized in repairing them. Plus they also guzzle a fair drop of diesel when in operation.

 We ended up installing 2 Detroit Diesel 8V71 550HP engines hooked up to Twin Disc gearboxes and Vosper V-Drives to power  41" NiAlu Bronze 3 blade propellers. These gave the vessel a maximum speed of 13 knots @ 2,100 RPM, a cruising speed of 12 knots @ 1,800 RPM and a passage speed of 10 knots @ 1,600 RPM. With our fuel tank configuration amounting to 17,000 litres, at passage speed, the vessel has a range of 1,400 nautical miles. Fuel consumption at passage speed including the use of a 42KVA Perkins Stanford generator is a very economical 120 litres per hour. We also have 2 additional generators including a 35KVA Ford Stanford and a 15KVA Onan (backup).

 Over the years, we've often considered upgrading to bigger engines to get her back planing again. From our own estimations, 2 diesel engines of around 1,800 HP to 2,200 HP would be needed to accomplish the task. Then again, the vessel was converted for pleasure and we've always been more than happy at 10-12 knots and enjoying economical consumption.

 From the data given to us, it appeared that in their days of operation, the vessels had around 10 tons of weight on deck from the superstructure and the armaments. This ruled out a steel superstructure as the sheer weight would have compromised the stability of the vessel and we wanted something that would add more value to the finished project than wood. Therefore we chose aluminium (8mm marine grade) as our weapon of choice, purposely built a hangar and constructed the superstructure indoors using around 9-10 tons of aluminium in total. When finished it was dismantled, transported in 3 pieces and lifted on board and secured. 

From there on, the interior work started, teak decks were laid as well as other works being carried out. As well as being supervised by a naval architect, the conversion was inspected by a surveyor from Bureau Veritas and was signed off no problem as a private pleasure yacht and until this date she is still registered under the British Registry of Shipping.

 After the conversion and refit was completed we motored her down to the Mediterranean ourselves with the help of a few friends. The seaworthiness of the Nasty class quickly became apparent when we encountered a force 9 strong gale in the Straits of Gibraltar punching into a 7 meter sea head on. We managed to motor through at our passage speed of 10 knots just taking slightly heavy spray over the bow. This was to be quite the envy of other yacht owners who were caught up in the same heavy weather, barely making a few knots of headway. A few of these yachtsmen came to see us in Gibraltar Marina to enquire how such a small yacht could just charge through such conditions with ease. From there on, we sailed to Malta where the boat lies to this day.

 She is currently undergoing her second refit. We have added a super yacht style aluminium transom, completely stripped everything down to the bare hull/superstructure and started again. We had the hull inspected by a Lloyds surveyor and its still in excellent condition after constant maintenance and dry dockings. We've never taken her out of the water on a slipway, we always put her into a floating dry dock to make sure the hull goes up and down evenly. She's currently at the motor away stage with the interior fit out to commence soon.

 I hope this is enough for you to go on. I attach a collection of pictures for you.

 Kind Regards



(email received 07-12-2013)

Hi Dan,

           I happened to come across your website as I was researching the Nasty/Tjeld class MTB's on the internet. 

We happen to own one of the surviving vessels built by Westermoen A/S in Norway (Lom). We bought her back in 1986 in the United Kingdom and converted her into a motor yacht and it is currently undergoing it's second refit. 

I attach a few pictures of when we bought her and 2 pictures of how she looks today.  

I notice from your website that you're always on the look out for information and the whereabouts for the vessels, so I thought I'd get in touch. 

It would be great to hear back from you. 

Kind Regards 

Rhodri McCarthy