Thursday, April 23, 2020

Watertight Doors and ABS - Part 3

In our previous post, we outlined the different types of watertight doors described by ABS.  We are continuing to examine the types of doors in more depth, and this post will be focusing on "Doors Used While at Sea".


Sliding watertight door for flood-control

These doors are the most expensive watertight door on the market because of what they need to do for the vessel.  Often referred to as "flood-control doors", they need to be able to contain a flooding situation in the compartment they are closing off,.  This means that the door has to:

  1. Close quickly in case of emergency
  2. Be able to be closed remotely (i.e. from the Pilot House) if no one is nearby to close the door in a flooding situation.
  3. Withstand enough pressure so that if the compartment fills completely, the door will not deform or leak.
  4. If there is a fire in the compartment, the door has to withstand temperatures over 500 degrees Fahrenheit, to prevent the spread of the fire to other compartments.
Flood control between compartments was addressed after the sinking of the Titanic in 1914.  These doors would not have been able to prevent what happened to the Titanic, since six of her compartments were ruptured by the iceberg.  However, there has been a huge effort to put safety measures, such as flood-control watertight doors in place, to prevent future tragedies.

We can work with you to help you determine the door that you need, and get you the door that best fits your needs.  Contact us for your watertight door needs.

More information on ABS: https://ww2.eagle.org/en.html

 

Monday, April 13, 2020

Watertight Doors and ABS - Part 2

In our previous post, we outlined the different types of watertight doors described by ABS.  In our next few posts, we are going to take a look at each type of door in more depth.  We will start with the category, "Other Openings Closed at Sea", which is the most common type of watertight door found on most vessels.


Watertight door installed, photo credit Pixabay
Watertight door installed
photo credit Public Domain Pictures at Pixabay
Cen-Tex #110 lever-operated
quick-acting door
These doors are the least expensive of the door types, and are the easiest to install and maintain.  A simple individually-dogged door will meet the ABS requirements for these opening.  If there will be lots of traffic through the door, then a quick-acting door is recommended.

For the individually-dogged door, there are the fewest moving parts that can fail.




The quick-acting doors have additional moving parts to allow all the dogs to operate simultaneously.  Quick-acting doors either use dog arms operated from a central hub, or use dogs on the perimeter of the door activated via a series of linkages.  These additional parts add to the maintenance, but knowing that the door is secured EVERY time you use it is worth it.

The wheel operation can be replaced with a lever to exert more leverage on the dog arms and make sure that they seal properly.




Close up of lever operated door dogs
Lever-operated doors with dogs on the frame are operated by linkages between each dog.  This requires more labor to assemble the dogging mechanisms, however, this mechanism creates a better seal than the wheel operated door with dog arms.  The dog rotating onto the panel provides more pressure at the edge of the door, more firmly compressing the gasket in the door panel onto the knife edge of the door frame.












These closures do not require remote indicators that the door is open or closed, and do not need to be able to be operated from a remote location (such as the pilot house), which greatly simplifies the installation and maintenance of the doors.

We can work with you to help you determine the door that you need, and get you the door that best fits your needs.  Contact us for your watertight door needs.

More information on ABS: https://ww2.eagle.org/en.html

Wednesday, March 18, 2020

Watertight Doors and ABS - Part 1

There are several types of watertight doors that are classified and approved by the American Bureau of Shipping (ABS).  The different types are:

  • Doors Used While at Sea: sliding doors capable of being closed remotely from the bridge, as well as able to be operated at the door's location on each side of the bulkhead.
  • Access Doors Normally Closed at Sea: heavy-duty bulkhead style quick-acting doors with dogs spaced to ensure that the opening gets closed and seals watertight. These doors must have a way of indicating on the bridge an open or closed condition.  They must also have a notice on the door to indicate that it is not to be left open.
  • Doors or Ramps Dividing Large Cargo Spaces: These watertight doors can be rolling, hinged, or sliding, and do not need to be remotely controlled.  They must be kept closed while the vessel is underway.  The time that the door is opened and closed in port must be documented in a logbook.
  • Other Openings Closed at Sea: These are doors, hatches, manholes, portlights, scuttles ... basically anything that is to be kept permanently closed while at sea, to ensure the watertight integrity of the vessel.  These do not need to be fitted with a device to operate them remotely, or indicate if they are closed, however, they do need to have a notice posted that the closure must remain closed while underway.  Manholes are exempt from this rule.
These different classifications for watertight doors will help you decide which type you need for your situation.  We can work with you to help you determine the door that you need, and get you the door that best fits your needs.  Contact us for your watertight door needs.

More information on ABS: https://ww2.eagle.org/en.html