by Captain Kirk Greiner, USCG (Ret)
Two articles on the manning of towing vessels appeared in the Spring and Fall 1988 issues of this newsletter. This article supplements those articles and is focused on a problem which has arisen from the reduced manning of tugs less than 200 gross tons.
In order to reduce costs, many companies have reduced the number of deck officers from three to two on vessels under 200 gross tons. Reductions of crew in other areas have also taken place. Some tugs have eliminated their deck crews and rely on engineers and the cook to handle the lines.
The result has been that the officers are working more than 12 hours a day.
At sea, the tug is usually navigated by a single operator who navigates, steers, and acts as lookout. With two officers, the watch is usually six on and six off. This is permitted regardless of the length of the voyage (Chief Counsel memo to Chief, Office of Merchant Marine Safety dated 14 March 1986, file 16721 G-LMI/426-1527 implemented in 46 CFR 15.705(d)).
One of the most difficult factors to assess in operation of towing vessels is the extent to which safe operations are potentially jeopardized by crew fatigue. Currently, the Coast Guard states there is no definitive indication of an industry wide fatigue problem. On the other hand, anecdotal data coupled with the rate of casualties attributed to operator or personnel error, and evidence that fatigue is a serious international concern (see IMO resolution A.772(18), Fatigue Factors in Manning and Safety), indicated a caution that fatigue cannot be ignored in an assessment of the adequacy and effectiveness of current manning requirements.
It may be possible in the future to establish work hour limits and manning requirements with a high level of confidence that those limits and requirements are adequate and effective. The Coast Guard is promoting research into the feasibility of a model which could calculate crew complements on the basis of workload assumptions, work hour limits, and reason projections of emergency situations.
The model is intended to take into account a wide variation in operating conditions as well as limitations in human performance (i.e., human factors). However, a working model will not be available for some time, and the feasibility of applying such a model to a towing vessel remains to be assessed and demonstrated.
In January 1990, the International Maritime Organization (IMO) Subcommittee of "Standards of Training and Watchkeeping" proposed a working definition of fatigue as follows: the degradation of human performance, the slowing down of physical and mental reflexes, and/or the impairment of the ability to make rational judgements; induced by such factors as prolonged periods of mental or physical activity, inadequate rest, adverse environmental factors, physiological factors, and/or stress or other psychological factors. The Coast Guard has identified two of the most frequent causes for towing vessels casualties: operator error (the degradation of human performance) and error in judgement (the impairment of the ability to make rational judgements). Both causes may be fatigue related. In 1990, The Transportation Safety Center (TSC) of the Department of Transportation, published the results of its study "Shipboard Crew Fatigue, Safety and Reduced Manning" (DOT-MA-RD-84090014, Nov 90, DOT, MARAD). While the study focused on seagoing ships, many of its findings, some of which are set forth below, are considered to be relevant to towing operations:
Merchant shipping is characterized by longer than average work weeks, nonstandard "work days," extensive night operations, and periods of intense effort, preceded by periods of relative inactivity. These factors result in sleep disruption and deprivation. Indeed, average hours worked per week are much greater on ships than in any other mode. Sustained periods without sleep (more than 24 hours) are also found more common than in other modes. On some ships, crew members experience the effects of fatigue (increased reaction time, reduced attention, diminished memory and mode changes) rather frequently. These effects are presumed to be major contributing factors in a large proportion of marine accidents.
Historically, most transportation accidents are attributed to human error. Lapses of attention are believed to be a major casual factor in operator errors which result in accidents. The major contributors to inattention are drowsiness, excess mental workload, boredom, and intoxication. Inattention may be under represented and actually be the initial cause for many casualty and pollution incidents.
An aviation oriented study indicated that fatigue and sleep loss can result in the following effects of performance: increased reaction time, reduced attention, diminished memory, and mood changes. This study also indicates that sleep deprivation leads to severe performance degradation. This degradation may be the result of: mood changes related to sleep deprivation include; heightening irritability and inappropriate feelings of competence; impairment in learning, reasoning, and complex decision making due to irrability; attentional lapses and resulting errors of omission.
The two-watch schedule used on towing vessels and shorter voyages allows a reduced number of deck officers but does not allow any more than six hours off duty. If no layover occurs in port and the watch schedule continues, the two-watch or six on and six off system will not permit readjustment of the crews' circadian-rhythms. Circadian-rhythms are a cyclic variation in physiological state, mental, and physical activity, roughly 24 hours in duration. Portions of the cycle have been identified with drowsiness and low performance. Studies have indicated that the effect of circadian-rhythm disruption on aircraft pilots may be more significant than the effects of sleep loss, even for short haul pilots who cross only one time zone.
At the present time, working limitations are set by statute and regulation. These are based on Congressional and agency judgements of the maximum period of time a person may safely work. On towing vessels, the maximum length of time an officer may work in a 24 hours period is 12 hours (46 USC 8104(h) and 46 CFR 15.705). The exception found in 46 USC 8104(f) allowing seaman to exceed their normal work limitation does NOT apply to officer work limitations found in 46 USC 8104(h).
This interpretation was reinforced by a 1991 court decision Sause Brothers Ocean Towing action for limitation, U.S.D.C, District of Oregon, January 24, 1991, Civil No. 89-609-RE, 1991 AMC 1242. In this case, a tug with an oil barge in tow approached the entrance to Grays Harbor, Washington.
The master's watch ended but he continued to navigate the tug while bringing in the towing wire and entering into the harbor although he had already stood 12 hours of watch in the preceding 24 hours. The tow wire broke and in recovering the barge, the tug holed it resulting in the second largest oil spill in Washington history.
The master stated that it was the company's policy for the master to bring the tug and tow over the bar.
The court stated ". . . the voyage distance . . . is sufficient to conclude that the violation of the 12-hour limit is negligent behavior on part of Captain May and of SBOT [owners] for failure to enforce compliance with the rule."
A recent (1995) personal injury case was settled under similar circumstances.
The Coast Guard has recognized that excessive work periods can result in fatigue and has addressed this problem in a recent study, "An Assessment of Towing Vessel Manning Requirements" prepared by the Office of Marine Safety, Security and Environmental Protection, July 1994. They reference the numerous statutes, regulations, Navigation and Inspection Circular 2-81 and Marine Safety manual as setting forth the requirements and policies relating to manning. Hidden in this study is a comment on the lookout requirement of Rule 5 of the COLREGS. In adopting the COLREGS, the legislative history includes the following statements:
On vessels where there is an unobstructed all-around view provided at the steering station, as on certain pleasure craft, fishing boats, and towing vessels, or where there is no impediment of night vision or other impediment to keeping a proper lookout, the watch office or helmsman may safely serve as the lookout. (Senate Report No. 979, 96th Congress, 2nd session 7-8 (1980); reprinted in 1980 U.S. Code Congressional and Administrative News 7068, 7075).
As previously indicated, towing vessel owners have reduced the manning on their vessels as a cost cutting effort. This frequently results in officers working more than the legal period of time. When a casualty or personnel injury occurs under these circumstances, one wonders whether they have really saved any money.
Some of the information in this article is taken from the Coast Guard study An Assessment of Towing Vessel Manning Requirements, July 1994.
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