Narrow Boat - Narrowboat - Narrow Boat Design

All narrow boats (narrowboat) normally have decks fore and aft. The after deck can be large enough to allow a passenger to sit with the helmsman when the boat is said to have a ‘cruiser’ stern. Some boats have a much smaller after deck and the helmsman can get some protection from the weather from the back of the cabin. It is this variation in deck area forward and aft that defines the various styles of narrow boat design.

So called cruiser style boats have a large after deck combined with a small fore deck or cockpit and are fitted with a long central cabin This type has a large flat rear deck which gives no protection but is large enough for several people to sit together on the after deck – a useful feature for young families and older folk. A seat for the helmsman or steerer is often provided.

Traditional style boats on the other hand have a reasonable fore deck but only a small counter deck at the stern for the helmsman. It is called the traditional (trad for short) style because it is similar in layout to the traditional working narrow boats. The cabin design follows that of the old commercial canal boats and refers usually to the size of the after deck or counter which is short in length with the steerer standing between the after doors of the cabin.

The advantage of a trad style narrow boat is that the steerer has a protected position against wet or cold weather and the additional advantage of the heat from the engine or the boatman’s cabin stove around his or her legs. There is also a very real feeling of closeness to the canal traditions. Friends can stand on the gunwales or sit on the roof. The main seating area is in the bow.

There’s an in between style which has some protection for the steerer and some room for passengers known as the semi-trad. This type has a large cruiser style stern deck enclosed by cabin sides and doors (but no roof), combining some of the advantages of both styles, and is becoming increasingly popular.

Tug style boats usually have a much longer fore deck and the cabin have scuttles instead of windows.

Narrow Boat Design

Narrow boats vary in length from 35 feet to a maximum of 70 feet overall but have a standard beam or width of six feet ten inches - nominally seven feet. The depth of the hull varies from about three feet six inches to four feet with a further three feet or so for the depth of the cabin. The maximum draft (aft) is usually not more than about two feet nine inches. Boats up to fourteen feet wide can be found and these area called in a somewhat contradictory fashion wide beam narrow boats.

The maximum breadth of the boat restricts the distance it can travel on the canal system and a good 'go anywhere' boat would be about 50 feet long by the nominal seven feet beam. The beam can vary and it should never be taken as read but should be measured at several places along the parallel mid body of the boat.

The majority of can boats have a flat bottom - some with a slight cut up at the forward end - although some boats - notably those built by Springer Engineering Ltd have a slight V to the bottom. Modern boats with a flat bottom have the bottom plate extended beyond the sides by up to one inch (25 mm) to form a so-called wearing chine. This construction also allows a better external weld between the side and bottom plates.

The sides are usually vertical and flat although some boats have the upper side plate tumbled home. The side decks are usually from four to six inches wide.

The scantlings or plate thicknesses are usually given in the order bottom/side/cabin thickness and are in millimeters. A good modern boat would be 10/6/4 mm.

The forward swim of the boat i.e. from the stem to the forward end of the parallel mid body is called the entry and the after swim from the after end of the parallel mid body to the stern is called the run. The flat counter plate above the propeller is called the uxter plate.

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