A narrowboat is famous for its small size and affordability. More importantly, it provides excellent living space for anyone wishing to spend time living while cruising on the water. When planning to live on the water, the first real job is to find the right narrowboat for your taste and preference. In this case, you have to choose either buying a new boat or getting a second-hand boat that you can fix it to suit your needs. In both cases, you have to ensure the boat you get meets all the minimum requirements necessary for life on the water.
The weight of a narrowboat is an essential factor when finding the right narrowboat. A boat with the right weight is stable and can float evenly on water, even on bad days. Therefore, you need to find a boat with the right weight. More importantly, you need to know how to estimate the weight of a boat. If not, you should find a professional to do it for you.
How to Estimate the Weight of a Narrow BoatEstimating the weight of a narrowboat is not only crucial for safety but also a crucial indicator of the maximum weight you can carry with your boat. You will use a similar approach as you use when calculating larger objects by adding the weights of all the components that your boat is made from. However, none of these calculations is as essential as displacement, considering a narrowboat is a floating vessel.
During boat construction, a boat manufacturer has to establish the depth that a boat will sink regardless of its seaworthiness. This is made possible by determining the boat’s displacement, referring to the amount of water a boat displaces when it is on water.
While the boat’s weight is fixed, the amount of water it displaces varies depending on various factors, including the amount of cargo in the boat, the passengers on board, food for the passengers, water, and other amenities like toilets and cooking equipment. In addition to this, the amount of water displaced by the boat depends on the water temperature and salinity.
Once you get the total weight of the material used in making the narrowboat and the variable weights to be shipped, you have to find out the volume of your hull. In the past, boaters used a planimeter. However, it has been replaced by computers in the modern world. The computer determines the water temperature and salinity.
There is also another method, far much more straightforward than the first method, but not easy. It involves weighing your boat on a trailer.
To do this, you will need to locate a weigh scale used by truckers near you and drive your truck pulling a trailer with your boat on it towards the weigh scale. Weigh the truck, trailer and boat, and record the figure in a book. Disconnect the trailer with a boat on it from your truck and weight the vehicle. Record the figure in a book. Remove the boat from your trailer and weigh the trailer. Add the weight of your trailer and truck then subtract from the total weight that included your truck, trailer, and boat weight. The difference you get from the final calculation is the weight of your narrowboat.
What Makes Up the Weight of a Narrow Boat?
A narrowboat has many components that give it its defining weight, which eventually gives it stability as it floats on water. Of all these components, the ballast is of great importance to a narrow boat’s balance and general design.
What is Ballast?
Ballast is simply a high-density material that is put under your narrowboat’s hull below the water line to mitigate the impact of weight on top of the waterline and maintain the stability of your boat in the water.
What is the Importance of Ballast?
A narrowboat is designed like a long rectangular box to maximize on its load capacity. The boat’s limited depth of water means that a keel is not fitted on the boat to enhance its stability. At the same time, clean water needs to flow along the boat’s hull towards the propeller, thus at the back of the boat under the water, the hull’s shape is designed to a point. This section of the boat is referred to as the swim.
The boat’s swim’s top plate, running parallel to where you steer and stand, is referred to as the uxter plate. The uxter plate has to be one or two inches underwater as a matter of importance to protect the propeller ventilation. On the other hand, ventilation is where your boat’s prop can receive air from resulting in poor and noisy steering. For this reason, your narrowboat has to be fitted with a ballast to keep it stable in water.
Safety and Stability
Every narrowboat should be fitted with the ballast with the safety and stability of the boat in mind. There is a regulation in place for commercial vessels regarding skin, weed hatch, and deck drains’ height. Even though these regulations are not mandatory for Private Craft BSS Examinations, it is essential for you to observe these requirements and regulations.
The Recreational Craft Directive determines some safety and stability parameters for narrowboat owners. Most people are not familiar with these regulations. Therefore, you need to consult your BSS Examiner or narrowboat shell builder for you to be safe.
Where is Ballast Fitted in Your Narrow Boat?
Typically, the ballast is installed in the shell directly on the boat’s bottom plate. Laying the narrowboat with ballast on top of its non-absorbent layer to set it apart from your boat’s hull steel is standard practice. If you can creatively incorporate an air space between the bottom plate and the narrowboat ballast, the overall effect will be even better. You can achieve this by laying the narrowboat ballast onto a spacer material that is not reactive like big plastic tiles.
You also need to treat the boat’s bottom plate using a thick layer of bilge paint to protect the steel from any condensation water that may be formed and any leaks in the future. Do this before fitting the ballast.
Types of Ballast
The market is awash with different types of narrowboat ballast. The most common type of boat ballast is the engineering bricks or concrete pavers. These materials need to be dense to avoid soaking up moisture that may get into the boat through bilges. You should go to class. An engineering brick is made to be strong and dense and has a rating of not more than 4.5% water absorption by mass. You can also use lead weights and iron ingots (view on Amazon). If you choose to use a metal narrowboat balance, you should have a protective layering to prevent it from coming to contact with your boat’s steel at the base plate.
You also need to secure the boat ballast from moving, more so when positioned in areas that are hard to access. A slight movement to the wrong side could change how your boat sits on the water.
Boat ballast contributes a lot to the boat’s overall weight. The type of boat ballast used is also necessary as some are made with heavier materials than others.
Narrowboats are fitted with water systems to meet the daily water demands of people living in the boat. Both the cold and hot water systems are included in a complete water system. Here are some of the fittings included in the water system:
- Wash hand basins
- Stainless steel sink
- Twin coil 1000mm x 300mm copper calorifier
- Toilet Mansfield Traveller
- Onboard tanks
- Radiators as appropriate, all fitted with thermostatic valves
In a complete water system, you can heat your water from a holding tank within the boat. You can also pump the water from the holding tank in your toilet. This tank is either made using plastic or stainless steel. All these components contribute to your boat’s overall weight.
The Hull and Super Structure
Here are the components that add up to form your boat’s hull and superstructure.
- Plank and pole rack
- Stainless steel water tank
- Steel hull and superstructure 10/6/4 plating by Daleside Welding or equal with four zinc anodes
- Painted in two colors to a simple design with PVC lettering
- Steel hatch
- Stern tube
- Windows by Caldwell Windows or Equal
- Rudder, brass tiller extension and hardwood handle
- Crowther propeller and shaft
- Pine front window frame and doors finished with Sikkens wood treatment
- Integral effluent tank, fuel tank and gas locker
Importance of Knowing the Weight of Your Boat
Knowing the weight of your boat is essential as it helps you determine the maximum load capacity that you can put on your boat. Given that a boat is a floating vessel, it needs the right amount of load for it to fit well on water. While the chances of a narrowboat being to light for floating is low, the real challenge is protecting your narrowboat from excess weight.
Knowing your boat’s weight is also important when making choices about haulage. Typically, boat weight is estimated to be one tonne per meter length. In the case of haulage, the company or person you hire to lift your vessel should have enough experience and should have sufficient knowledge about estimating your boat’s weight from previous lifts and scales on all of their equipment. There are companies that have specialized in moving narrowboats. You should seek their services in this matter as they have a better understanding of boat weights. They will also come prepared with the right track.
If you want to get a more accurate weight figure of your boat, you should measure your boat’s draught midway along your vessel, as well as the length of the back and front swims. Remove the length of the swims from your boat’s length and multiply what you find by the beam and draught to find the cubic meter. Add the length of your boat’s two swims and divide the result by two. Multiply your answer with beam and draught to find the cubic meter. Sum all your answers. Given that one cubic meter of water is equivalent to 1ton/tonne, you can convert your answer t weight to get an estimate of your boat weight in 1ton/tonne,
The weight of a narrowboat differs based on size. Longer boats weigh more than shorter boats. When on water, these boat’s weights vary based on the load. You, therefore, have to ensure you load your boat with the required weight to keep it balanced on water. In case of haulage, you need to find an experienced company to handle your boat, especially one that has specialized on narrow boat haulage.