boating information
glossary
The following is a guide to some of the terms used to describe parts of a narrowboat. Many are derived from old working-boat terms and have taken on a new meaning in the days of leisure boating, but most are as relevant now as they ever where.
For a very comprehensive glossary, particularly when it comes to historical terms, see http://www.jim-shead.com/waterways/glossary.php
- Ballast
- Heavy material, often concrete slabs, laid on the base plate to lower the boat in the water, increasing stability.
- Blacking
- The coating on the hull below gunwale level, usually based on bitumen or similar. Usually recoated every two or three years.
- Barge
- Usually a broad-beam commercial boat, often unpowered and without a cabin top (unless a Dutch Barge). A term guaranteed to upset any narrowboat owner when applied to their craft.
- Beam
- The width of a boat at the widest point. Modern narrowboats are usually built to a beam of 6’ 10” and narrow canal locks limit the width to about 7ft (or slightly less in one or two notorious cases).
- Butty
- An unpowered narrowboat towed by a powered boat (the “motor”) together making up a pair. Usually seen nowadays as a hotel pair. Note a chip butty is something completely different.
- Counter
- The flat rounded area at the stern of a trad-style narrowboat. Also used to describe the flat area below the waterline either side of the ‘swim’.
- Dolly
- The small steel uprights on the rear deck used to attach mooring (or towing) ropes to. Often mistakenly referred to as a bollard.
- Draft
- The distance from the waterline to the lowest part of the hull. It is usually nearest the stern and increases with more revs, so if it does touch the bottom the best action is to gently reverse off rather than trying to power through.
- Freeboard
- The distance from the waterline to the lowest opening in the side of the hull.
- Fender
- A buffer, usually of rope, attached to the bow and stern of a boat to prevent damage. The stern one should extend further than the rudder and is also known as a tipcat.
- Gunwale
- The narrow side-deck at the top of the hull where it turns in to the cabin sides. Pronounced “gunnel”.
- Keel cooling
- A closed engine cooling system, similar to a car, but where the radiator is replaced by a thin tank welded to the inside of the hull. As for a car it requires anti-freeze to prevent damage from freezing. See ‘raw water cooling’.
- Narrowboat
- In current usage a narrow boat built to a 6’ 10” beam used for pleasure purposes. However not all narrow boats are narrowboats.
- Ropes
- Used for tying up a boat. May be referred to as a strap but, sailors please note, never ever called a sheet.
- Raw water cooling
- An engine system where cooling is achieved by drawing water in from the canal. This can be either direct, where water from the canal is pumped directly round the engine, or indirect where the water is pumped through a heat-exchanger. Whilst such a system is normal for boats used in deeper water, the shallowness of the canal and presence of weed means that most narrowboats are installed with keel-cooled engines.
- Skeg
- A steel bar extending from the rear of the swim to provide support for the lower end of the rudder post.
- Slide
- A sliding hatch cover over the rear doors to give easier access to the cabin. May sometimes also be incorporated over the front doors
- Stem
- The front of the bow. The stem post is the structure at the front of the bows.
- Stern tube
- A tube through the rear of the boat to carry the propeller shaft and providing a waterproof seal. Can be either a water-lubricated seal or a ‘stuffing box’ with an adjustable end. The latter requires grease to be pumped in on a regular basis.
- Swim
- The tapering rear end of the lower part of the hull, coming to a point underneath the counter where the propeller shaft exits. It allows a good flow of water around the propeller.
- Tumblehome
- The inward-sloping cabin sides. Traditionally towed butties had more tumblehome to give better clearance under bridges. Now more likely to be determined by the width of steel plate used by a builder for the roof.