Human Factors Engineering deficiencies in ship construction
Even though naval architects and marine engineers typically design a ship to a fine level of detail there is usually still some leeway left for the shipyard personnel to move or make adjustments to piping, equipment and wireways during the construction phase.
For example, the final placement of pipes below 3/4” (19.05 mm) in diameter is often left to the pipe installer. In making these ‘field run’ installations the pipe fitter may not be aware that a particular area may have been left open on a bulkhead, or overhead, as pull space for the removal of a piece of equipment. All the pipe fitter sees is an opportunity for an easy run of pipe.
A second potential problem arises when a previously undetected interference occurs between piping and structure, or between structure and a piece of equipment that turns out to be bigger, or different in arrangement, than was shown on the design drawings. These unexpected hits are sometimes solved ‘in the field’ by the movement of pipe or equipment by the construction crew. However, in doing so, this ‘field correction’ introduces Human Factors Engineering (HFE) problems such as unacceptable access for equipment removal or the placement of a control or display beyond the operator’s acceptable visual or reach envelope.
Another HFE problem that often occurs during construction involves vendor- supplied equipment that has been integrated into the design of a space on the ship without proper consideration by the design engineer as to the equipment’s installation, maintenance or operational requirements. As a result, sufficient access to a system’s access ports and openings for calibration, installation and repair, or its controls and displays, or simply the clear space required around the equipment for equipment movement or product protrusion, has not been provided in the design phase and must be corrected during construction. This can lead to a need to move equipments, provide elevated working platforms or add or relocate lighting fixtures, all of which have HFE implications.
The picture below shows two small pumps sitting one in front of the other in a cruise ship main machinery room. The two control boxes however are sitting side-by-side as faced by the operator. As a result there is no visual spatial relationship between the pumps and their respective controllers. In other words, if I ask you to select the control that turns on the aft pump which control box would you reach for? This is a perfect example of a HFE design deficiency that should have been detected and corrected during construction, but was not.
Because of the frequency of these construction identified or created HFE problems shipyards have adopted different approaches to ensuring that they are identified and corrected. One approach has been to provide in-house construction inspectors with a short but specialized HFE training program. Another has been to offer a similar training class to construction trade supervisors and leads. Both training sessions include a brief description of what HFE is; what has been done during the design phase to include HFE into the ship’s design; examples of typical situations that occur during construction that can introduce a HFE problem; and typical activities that might be undertaken by construction personnel that should alert them to ask for HFE assistance or evaluation before proceeding with the ‘field run fix’.
A further approach is for the shipyard to employ a HFE specialist who will make frequent and periodic visits to the construction site (this includes not only the shipyard but also the fabrication sites of vendors supplying hardware for the ship) to seek out HFE problems which have been created during the construction phase, and get them corrected before the construction is complete.
HFE deficiencies not detected or existing during the design of a ship, can be identified, or can be created during that ship’s construction effort. This is a common and frequent occurrence that can provide opportunities for human errors to occur on the ship once in service, and thus must be eliminated wherever possible. However, there are techniques to identify and correct these HFE deficiencies before the ship leaves the yard - a good ship design and construction program will seek to find and eliminate them.