The Birchwood Intercepter was designed by Ted Andrews and unveiled in 1968.

There are two theories about the unconventional spelling of "Intercepter". One is that Birchwood wanted to avoid a legal quarrel with Jensen Motors, who had a model called the Interceptor at this time. The other theory is that workers at Birchwood were too afraid to tell the boss he had spelt it wrongly!

The boat was a 4 berth cabin cruiser, capable of coastal use. The hull was good for speeds of up to 30 knots, although with the usual Mercruiser 120hp on outdrive its top speed was nearer to 20 knots and it cruised comfortably at 15 knots.

Length over all was 25ft 0in (7.62metres) Beam 9ft 3in (2.82metres) Draft 1ft 3in (0.38m) and Displacement 1.86 tons.

In 1974 a new river cruising derivative called the Birchwood 25 was introduced. It had a longer hardtop & a wraparound canopy. A shaft driven version was introduced for river use. A quarter length propeller tunnel was built into the bottom of the boat permitting the drive line to be kept short enough for the engine to remain beneath the cockpit. The engine was a Watermota Sea Tiger (based on a 1600cc Ford Kent crossflow) which gave a claimed 78hp and about 10knots at full revs.

The tunnel prop had two problems at first... a plume of water behind the boat and a tendency to wander. The water plume was fixed with a deflector plate on the transom, and an optional steel keel was introduced to improve low speed handling.

The keel increased draft to 2ft 1in (0.64metres). Most shaft drive boats were ordered with the keel.


In 1978 the Executive has introduced. This had a larger heads compartment with a shower. It also has the longest hard top and rear seat mouldings and can sleep 2 in the cockpit.

A range of engines was now available, including twin 145hps on outdrives. The shaft drive boats remained a popular option.


In 1981, after production of about 1500 boats, production of the 25 ceased as Birchwood went upmarket to build larger boats.


Known problems on Birchwood 25s

Poor drainage of hardtop leading to leaks into cockpit.

(I drilled two holes at the REAR end of each gutter. Some of the water pours down the canopy, but it has reduced the leaks inside!). I cannot guarantee it will work for you, do this at your own risk etc.

Fuel line detatching from carb on Sea Tiger engines.


Drive shaft coupling failure on shaft drive boats.

This happened to my boat... the cotter pin wears its hole into an oval and then breaks (repeatedly).  The fix is to remove the old coupling and fit a modern clamp type coupling. However, as the J type gearbox has a 3 bolt flange the new coupling (which will be a 4 bolt fixing) has to be machined to fit.

Wobbly deck fittings and pulpits.


Copyright Birchwood Owners Association.

Further reading:

Motor Boat and Yachting September 1997 P168 & P169.
Practical Boat Owner November 1975 P56 & P57.
Motor Boat Monthly May 2003
Motor Boat Yachting May 2004




   

We bow before you O' master!

Great little read there  

I can relate to the fuel line problem for sure.  Very well documented, ta  ;)  

--Last edited by flashheart on 2008-05-05 18:25:56 --