How Do Bulkheads Prevent a From Boat Sinking?

What is a bulkhead? A bulkhead is an upright partition that separates two chambers. In Old Norse, the word bulky would mean “cargo”. Sometimes near the 15th century, some of the sailors and builder in Europe discovered that the walls within the boat could avert cargo from shifting during the passage.

Any vertical dashboard was called a “head”. So walls that were placed abeam in the boat’s hull were known as “bulkheads”. Now except for the hull, every vertical dashboard or walls are called bulkheads.

The Purpose of Bulkheads

Bulkheads increase the constructional rigidity of the boat. It separates the useful areas into the rooms and makes watertight compartments which can accommodate water in a case of emergencies, such as a hull breach or other setback. Some of the bulkheads are fire-resistant.

They also carry out some of the other functions as well, like they act as systematic members in the ship and give the power to withstand various kinds of transmitting to the boat by the sea, for example, sheer load, twisting load etc. 

The minimum amount of bulkheads that a ship must have is 3, which are known as aft bulkhead, forward collision bulkhead and engine room bulkhead.

However, they can always be more than three, depending on the blueprint of the ship and the characteristic of floodable length and compartment qualities.

Requirements of Bulkheads

Down below are two compulsory requirements that a bulkhead must meet in order to be worth the purchase.

Fire Resistance

To reinstate the fire resistance ratings which could be at risk if the openings in fire-resistance-rated bulkheads and decks are not fire-stopped. Leaving them not sealed could create a significant hazard.

Prevention of Damage from EMI and EMP

Bulkheads and decks of ships are always fully kept electrically grounded so that an action could be taken at all cost. When it encounters danger or threat against destruction from EMI and EMP due to the nuclear or electromagnetic bomb explosion near the ship, which could ultimately damage the whole electrical system of the vessel.

In case there is a fire hazard, the cables are plugged out, and fire-stop rubbers are fitted inside with some copper shields.

The Types of Bulkhead

The strength of watertight bulkheads is one of the most significant factors that make sure of the safety of the damaged ship. Some other factors need to be paid attention too as well, in case of designing them.

Watertight bulkheads are designed in a vertical way against the wall to avoid the entry of the water in the compartment and stop the possible flooding that can happen in the hull. We are about to now look at the types of Bulkhead that can be present on a ship.

After peak Bulkhead

The forward borderline of the aft peak.

Collision Bulkhead

The top-level main oblique watertight Bulkhead, which in such a way that it keeps water away from the forward hold in times of bow collision damage.

Corrugated Bulkhead

Bulkhead with wrinkled plating which replaces the need plans of connected stiffeners.

Engine Room Bulkhead

A crosswise bulkhead which is either directly in the direction of one is travelling or aft of the engine room.

Portable Bulked

It is a Bulkhead that removes at any time. The construction is entirely made of steel which can join two separate compartments.

Strength Bulked

The Bulkhead that puts up with the power of a ship.

Swash Bulkhead

When the ship rolls and pitches bulkhead that is contoured in-tank lessens the outpouring of the fluid and also lowers the dynamic impact of the liquid on the adjacent structure.

Why the Boat Sinks?

As we all know, boats are commonly made to float on top of the water. However, accidents are unavoidable, and you know how there is a saying that you can never predict the unknown.

Also, aren’t we all already aware of all the mishaps that can happen when a boat or ship sinks? There are lots of things that can go wrong when your boat decides to be a submarine.

Winning over water is inescapable, enormous, massive waves always break the sides of the ship and also create small leaks at times. These are the most common boat defects that can be found.

Water always finds its way to the lowest part of the ship, which is known as the bilge area, where the bottom curves will see the sides. The water that stores there are also known as the bilge.

That’s why boats always have bilge pumps in store so that when the water reaches a certain level, it can guide the water back to the sea. Let’s look at some of the main factors that might be the reason behind a boat sink.

Low Transom

A flat vertical surface which forms the stern end of a boat is known as the transom. The motors are mounted onto the transom when it comes to the outboard boats. Sometimes in inboard vessel cases, the names of the boats are written on them.

The whole plan of designing the position of the transom is that it would not touch the water. Flaws in designs could leave it too low at times. Not maintaining proper weight distribution can also lower it, so that waves could reach the transom and flood the deck.

Not storing all the heavy gears in the stern would prevent this from happening. Distribute the weight of the heavy equipment like coolers, fishing equipment, bait etc. evenly so that the height does not get affected by it. Also, do not anchor from the stern side that might even bring the transom down. 

Missing Drain Plugs

Boats usually sink due to absent drain plugs. The entire ship sits higher on the water than it did when it was at rest while the ship is moving forward, which also makes the front more elevated than the rear.

There is a drain that is placed at the rear of the boat. This factor allows the water from the sea or waves that have entered the boat to exit. When you are moving forward on a boat, and when it tilts up, that’s the time when water flows towards the drain and back into the sea.

The chaos occurs when the captain of the ship forgets to watertight the drain to stop while the boat is at rest. The boat sinks lower and starts to take on in water through the drain when it is at steady state.

To prevent such cases, we could carry extra drain and also keeping them near the ignition is a better choice.

Cooling System Leaks

The engines of the boat are always water-cooled, for a 300 horsepower engine they pump about 30 gallons of water through the process. Sinking can occur if liquid gets collected in the bilge, which might happen due to hose bursts or the hose is not tight enough.

Double-check the hoses and cooling systems before you start to sail, replace if anything seems fishy or at fault. 

Navigation Error

This error means when your boat would directly hit an object. It could be anything like rocks, logs, ices etc. anything huge enough to damage your boat’s hull or body. All you have to do to prevent such a mishap is always being careful.

And, keeping your eyes forward for any obstacles. Slow down at times if you need and watch your moves and turns, and sail cautiously.

How to Survive a Boat Sink?

Staying calm is the first rule during the boat sink. Do not panic, which can create much greater chaos than the whole situation itself. Everybody which includes the captain and the passengers need to work together to take actions and gather all the flotation devices immediately and also have the life raft prepared. Use the radio for help, and you must give your exact location coordinates. Emergency items should be put together as soon as the raft is ready.

Emergency items should be prepared beforehand like:

  • Flashlights
  • Freshwater
  • Food rations
  • Sunscreen
  • Radio
  • Matches
  • First aid kit
  • Batteries

Keeping everyone calm and working together can keep the boat above water for a while, and also maybe you would be able to reach the life raft safely without any harm. Follow the captain’s direction.

How Does Bulkhead Prevent Boats from Sinking?

Bulkheads do not prevent the boat from sinking, but yes, watertight compartments can. And watertight compartments are a part of Bulkhead.  The weight of the boat needs to be much less than the weight of the water that has been displaced, to prevent the boat from sinking.

When a boat is large enough, Bulkhead becomes a part of the boat either if you create your watertight compartments with bulkheads or not. Bulkheads become an active part of the boat.

Bulkheads need to be in a position that the watertight compartments are enormous enough to come up with significant flotation and also the bulkheads need to be watertight plugged, with accessible hatches and doors on the other side.

Positioning the Bulkhead for small boats such as under 60ft is the tricky case. Because if it’s not placed in the right position, huge collision or mishaps can occur when the Bulkhead comes near the hull.

If this ever happens, it ruins the whole chance of bulkheads ever preventing the boat for sinking and also destroys the entire ability of water-tightness from both the sides of the Bulkhead.

On the other hand, when it comes to larger boats, designing the watertight bulkheads can lower the chance of sinking the boat. We all have seen the movie Titanic, haven’t we?

There is a myth which believes that the ship missed out to put watertight tops on the waterproof compartment on their designs, so now we all know why Rose and Jack didn’t have a happy ending. Double-checking every single detail is very important when it comes to building or even sailing a boat.


Now, as we have gone through all the points that could cause a ship to sink. And, also looked at the necessities of a bulkhead with the help of this article. I hope you will have a safe sail on the water and remember always to be ready to take safety measures as soon as possible.

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