Instant buoyancy

At 0100 on Dec. 6, 1999, Norwegian sailor Petter Noreng was awakened from a deep sleep on his yacht Jägermeister and asked to lend assistance on the foredeck to handle a fouled spinnaker. As captain on this transatlantic voyage, he had ordered all crew to sleep in their harnesses so that there would be no time lost in donning the gear if immediate assistance was required on deck. He would owe his life to this decision.

He had been sleeping in his clothes and was wearing his PFD, one of the inflatable harness variety, and so when he responded to the call for help he was actually on deck in seconds. A moment later, as he was working his way forward, he was caught in the head by the boom, which had been thrown into an accidental gybe. He was launched over the side into the darkness. As he watched his boat slip farther away, he started treading water and remembered his inflatable PFD, which he then manually inflated by pulling the lanyard. He spent the next 18 hours adrift in the warm ocean, 700 miles east of the Windward Islands, until the crew of another vessel pulled him aboard at dusk the following day.

The decision to purchase an inflatable PFD as a primary life-saving device is fraught with compromise: there is the price, which ranges from $100 to $300 depending on options and basic quality; comfort is an important consideration, since a device like this will only be used if it is comfortable enough to be worn most of the time when working offshore; and it is equally important to be concerned about reliability. One’s life depends on the ability of these devices to be inflated by a cylinder of compressed carbon dioxide, either automaticallyby a water-activated sensoror manually. (All units can also be inflated by breathing into a valve like the buoyancy compensator, B.C., found on scuba gear.)

Noreng had the perfect gear for the task. He was able to wear his PFD in his bunk, and so he was able to stay afloat when he suddenly found himself swimming. But can these devices be depended on to work all the time? It is quite unlikely that Noreng would have survived if he had not been wearing a PFDwhich means that had he not been using an inflatable PFD, he would not have had a PFD on at all. But if he had been knocked unconscioushe later described his concern over a seeping head woundhis choice not to have an automatically inflating PFD would have been fatal.

In November 1996 the U.S. Coast Guard approved certain manually inflating PFDs for use on vessels in the U.S. and labeled them as performing to the standards set for Type III PFDs: good for general comfort and designed to keep someone upright, but not required to right the unconscious wearer to a face-up position. PFDs fitted with a harness qualify as a Type V, which means they have a special purpose and are marked as a substitute for Type III; they can be used to the same requirements as Type III if used in accordance with the conditions on the label. The “Think Safe” pamphlet attached to every PFD when it is in the store clarifies all five types and their performance data.

Inflatable Type I and II PFDs have 150 newtons (33.7 lbs) of buoyancy, and inflatable Type III PFDs must provide 100 newtons (22.5 lbs).

In August 1999 the Coast Guard approved certain PFDs to have a manual inflation device with automatic back-upapproved as Type V inflatable PFD with Type II, capable of righting an unconscious victim face up, or Type III, not required to turn a victim face up. This is not to say that in function the automatically inflating PFDs are not able to perform as the primary inflating mechanism. But in the Coast Guard’s opinion, Type II automatically inflating PFDs cannot be “approved unconditionally” unless a person can check the CO cartridge at a glance, rather than by removing the cartridge and checking to see if the seal is broken. All manual/auto inflatable PFDs on the market today require this procedure.

“It is our main concern that people who are using inflatable PFDs take the time to remove the CO2 canisters and check the seal. This should be done with regularity,” said Dan McCormick, project engineer for the Lifesaving and Fire Safety Division at Coast Guard Headquarters in Washington, D.C.

In general, the Coast Guard is supportive of inflatable lifejacket use, provided they are used with common sense and understood to be different than closed-cell foam PFDs. “Right now people are drowning because they are not wearing lifejackets. If inflatable PFDs are going to get people to wear them, we encourage boaters to have them,” McCormick said. Another option for sailors who want to use inflatable technology without the inflatable harness is the inflatable belt-pack, which are approved Type III PFDs that can be used in conjunction with a standard sailing harness. The Coast Guard encourages people to wear these belts with the inflatable section in the front or to the side, not in back, since in-water donning could be more difficult in this position.

To complicate matters, inflatable PFDs also need to qualify (for the offshore sailor) as capable harnesses, which makes selection of a PFD more involved. The Coast Guard does require inflatable PFDs with integrated safety harnesses to meet the Offshore Racing Council’s (ORC) harness requirements to gain approval. In a recent study by The Sailing Foundation, a non-profit organization dedicated to promoting sailing in the Pacific Northwest, just about every harness and inflatable PFD on the market was subjected to a battery of tests. (The report is available by sending $21 to The Sailing Foundation, Box 4213, Tumwater, Wash., 98501; tel: 360-754-6506.) The section on choosing a harness and inflatable PFD is worth repeating: “Our ideal harness would be easy to adjust and lightweight. It would be easy to don, and not be too hot. It should have reflective tape on the shoulders and a place for extra gear, such as a strobe light, and a flare. We prefer two attachment rings for redundancy. The stitching would be a contrasting color from the webbing for easy inspection, and the material would be supple for comfort on bare skin There are advantages and disadvantages to having automatic inflation. Obviously the automatic inflation will give you a better chance if you get knocked unconscious by going overboard, but the manual unit is Coast Guard approved and it shouldn’t inflate from getting doused on the foredeck (although the current generation of auto-inflating products is improved over the previous).” The report concluded that none of the products available were all of these things at once, but many came close. Several manufacturers and the non-profit institution U.S. Sailing recommend that sailors venturing offshore purchase a PFD with 150 newton of buoyancy, which can keep a lean and muscular 300-pounder comfortably afloat and in the necessary position. (Someone with a high percentage of body fat of equal weight might require less buoyancy.)

Underwriters Laboratories’ (UL) marine division near Raleigh, N.C., will be reviewing several cylinder seal indicators this spring. Coast Guard-approved automatic-inflating PFDs equipped with cylinder seal indicators will likely be available by early 2001, according to several manufacturers and Coast Guard officials. The Coast Guard considers recommendations of UL that follow their rigorous product-testing program before establishing a regulation. An engineer at UL described the inflation device and outlined certain precautions for their use.

>”Certainly these devices need to be inspected; the water sensing element [for auto inflation models], and the whole thing needs to be in good condition. If you’re the type of person who’s going to leave it in the trunk of your car for a year, grab it and go sailing, then an inflatable PFD is not a good choice. If you treat it with care and understand the limitations and respect it, there are a great deal of benefits in use and performance,” said Dan Ryan, associate managing engineer for Engineering Services.

If using the manual-inflation models, the main area of concern is the cylinder seal, a corrosion-resistant metal plate. Once the pin punctures the seal the cylinder is expended, and it should be discarded and a replacement installed. A giant leap in respect is required for auto-inflation models. For instance, a cellulose tablet, which keeps a spring under tension, is obviously sensitive to moisture, whether humidity, rain, or wave splashes. UL engineers tested rain and splash guards, and even a humidity-venting system, but judgment is the best tool in determining their safe use. “There is a degree of resistance to all these effects, but at the same time we don’t want to have the PFDs lacking in sensitivity, since the bothersome nature of them activating accidentally is offset by the alternativenot deploying when they’re really needed,” Ryan said.

Cold weather also effects all inflatable PFDs, since temperatures below freezing can turn the CO to dry ice and retard deployment time. UL recommends not using inflatable PFDs in temperatures less than 32°F.

The ORC and U.S. Sailing both recommend using inflatable PFDs with crotch straps. Another feature recommended by ORC is the face shield, a screen of transparent plastic sheeting that protects the wearer’s face from waves.

Regardless of their limitations, inflatable PFDs represent a safe way to manage the risk of going overboard and being lost, provided they are treated with care. Certainly Petter Noreng would agree.

By Ocean Navigator