Retro-fitting Process

Steps in the Retro-fit Process

To get an idea of what it takes to retro-fit a ship watch the timelapse video (5:43) below to see the steps involved in retro-fitting a ship to add a second hull in order to create an innner liner to hold crude oil.

1. Design

The scope of a retrofit can vary from a minor change to a major overhaul. Small changes may be handled by the ship's staff, but significant changes usually require input from ships engineers. The engineering capability may exist in-house or the work may be contracted out, especially if a new technology or design requires specialized knowledge. Once design expertise has been identified the first step is to draft preliminary drawings for the owners. This cycle of drafting and reviewing may be repeated several times until the full scope of the retro-fit is understood. For example, replacing a main engine could also require additional air intake, cooling capacity, and rewiring of the control panels in the engine room and on the bridge.

Often ideas that seemed simple at the outset grow in complexity to the point that the owner may decide the project is not financially feasible, or the vessel downtime is too long. During this design phase, the naval architect, hull personnel, mechanical and electrical engineers will all have input to ensure that the plans for retro-fit are feasible.

2. Design Approval

If the preliminary design and drawings are approved by the owners, the engineers will draft working drawings and begin to specify the required materials. The engineering package (drawings and material specifications) become the property of the ship's owners.

At this point a sole-source manufacturer may be identified or the work put out to bid. As part of the bid process contractors will raise any design considerations that could cause significant deviations from the draft plans. Minor changes to the contract are usually entertained if the cost is relatively inexpensive and if the schedule is not affected. However, if the costs beyond the agreed price, or the work has the potential to affect the ship's sailing time, the owner may choose to retender the contract.

It is often the case that there will be minor deviations from the design once the work begins. Typically these changes are made and the shipyard bills the owners accordingly. These types of design changes routinely occur when a fleet of ships are maintained by different yards, or if the shipyard workers were referencing original drawings that do not reflect the current state of the vessel.

3. Lockout and Isolation of Systems

Before physical work begins on a vessel, any of the "systems" affected by the work will be inspected and then specific areas will be isolated, or locked out, to prevent accidental energizing. For example, if ship stability is being improved by welding baffles into a large onboard tank, all electrical controls for pumps and transfer systems would be electrically locked out, and the large valve wheels chained shut to prevent the movement of fluid once workers are in the tanks. Adherence to stringent lockout procedures occurs when work is done on salt water systems, potable water, black water, electrical power generating devices, heating, ventilating air conditioning units (HVAC) and even on radar or navigation equipment that could accidentally transmit ionized radiation. These systems have the potential to harm or kill humans. Accidental discharge of deleterious substances such as refrigerant or sewage can also do untold environmental damage.

4. Clearance from the Ships Representatives

In commercial shipyards, work can only start once the ship's representative gives approval. Formal approval is one way to manage what is known as "scope creep" – in a nutshell, when more work is done than was initially agreed to. For example, imagine some new furniture is being fitted in the main galley and during the installation some paint gets scuffed and marked. While it may be in-scope to touch-up the damaged paint, it would be out-of scope to paint the entire space. If the contract did not call for painting, but the yard went ahead and did it anyway, they would not legally be able to collect money for the work because it had not been pre-authorized. Ship's representatives will have different approval levels to pay for work that may fall outside the contracts. Workers themselves should never take on jobs requested by the ship's staff, but rather refer the request to a supervisor who can seek approval or denial from the designated representative.

5. Hazard Assessment

A critical step prior to the start of work is to assess potential dangers. Even routine work like painting can become hazardous if emissions are not contained. Yard supervisors will evaluate potential dangers by reviewing written assessments that are kept on file.

These assessments are reviewed prior to the start of work so that preventative measures can be taken: some examples might be temporary ventilation, heavy draping of an area with boundary tarps, or scheduling work for different shifts. Hazards might also be managed by posting warning signs or using sentries to keep workers out of an area.

6. Preparation for New Assembly

When new assemblies are to be fitted to a ship's hull, the immediate area must be properly prepared to accept the new pieces. Some parts may be very small, like brackets or hinges, and other pieces may be huge like winch bases or entire living quarters. Whatever the size, surfaces must be prepared for welding, bolting, or other methods of fas-tening. Piping and electrical concerns around the new equipment must also be dealt with.

If the new piece being attached is to be welded to the ship, the area must be stripped to bare metal and the surrounding area made gas-free (to reduce the risk of welding sparks triggering an explosion). All exposed areas or open lines that could be affected by the welding must be protected through the use of appropriate safety gear: this must happen whether the item is a new door hinge or the base for a new engine. The scope of the job may increase, but the same care must be taken. Safety preparation is usually specified in the work order, but it is incumbent upon workers to understand the job so that upon completion all the parts and pieces are properly re-assembled. It is also necessary to touch up paint, re-attach lines and in some cases to "prove" the system by testing cooling lines, re-attaching electrical gear, and generally ensuring that the space is returned to its original condition.

7. Removal and Bracing of Structures and Systems

When retrofitting a ship, there may be a need to remove extensive amounts of equipment and in some cases, even bulkheads or decks to facilitate the installation of large pieces of machinery. When removing large parts of a vessel the ship's drawings must first be reviewed to identify strong and weak points.

Once work has been completed, these temporary structures must be removed with care. Beams should be secured or tied off before they are knocked down with hammers or mallets, and whenever possible, piping and electrical systems should be affixed to their new mountings prior to the temporary mounts being removed. Careful removal will ensure proper alignment and prevent stress from being applied to the wires or piping.