If you were asked to put one of these on your head and go for a stroll around a wreck, would you fancy it? That's what we thought, but Frank Allen swears by his Snead helmet...
I slipped over the side of the boat and allowed myself to sink shoulder-deep on the shotline. Someone handed me a nose-clip. There was a sudden hiss as a cylinder was turned on in the boat and the air supply checked over.
"Ready"? asked a voice. I nodded and looked up. Two pairs of hands lifted the bulky cast-iron helmet over the side and eased it over my head; its 27kg settled firmly on my shoulders, pushing me under. Green water rose quickly over the visor as I dropped half a metre, but inside the helmet it stayed level with my chin, lapping around my ears as if I were treading water. It was a familiar and reassuring feeling.
I adjusted my grip on the shotline as a safety diver looped the air hose under my left arm, holding it up for me to take. I grabbed it and made ready for the descent. Thirteen metres below was the wreck of the Abelard, and although I had swum around its boiler and scattered remains many times before, this was to be my first walk on the site. It was also to be the helmet's first sea dive...
Open-helmet diving was an early form of our sport which briefly reappeared between the two world wars and was made famous by a variety of people whose diving exploits were heavily publicised.
Some, like William Beebe, used the open helmet to carry out serious scientific research underwater, while others used it as a means to paint or sketch underseascapes: a highly original thing to do in those days.
Explorers and adventurers were also in on the act, their books invariably featuring photographs of plucky amateur divers making daring descents into the unknown. Even the teenage Hans Hass was at it, walking across the River Danube under water and emerging to the rapturous applause of spectators - and the mother of all headaches.
This was diving at its simplest. All you needed was a weighted box or drum with a window cut into it, a convenient length of rubber hose, a hand-pump, and a willing assistant to do the pumping. In the event of an emergency, which was usually a pump failure, all you had to do was throw off the helmet and make a free ascent to the surface. Anyone could do it.
To prove the point, women were photographed diving, an unheard of development in an age in which the only female divers were mermaids.
By its nature, modern open-helmet diving was a warmwater pursuit, and it was in the USA that it really caught on. Professionally made helmets and pumps were produced there, and this was the first time diving equipment had ever been made for recreational use. Morse, Miller-Dunn, Desco, and Snead were among the leading manufacturers in this field, and so successful were their helmets that many of them remained in use long after the birth of the aqualung.
Today, these helmets and their place in history are largely forgotten. Few exist outside private collections and the odd museum, although occasionally they do turn up unexpectedly elsewhere.
I found mine quite by chance, in an antiques shop. It was hiding in a corner as if ashamed of itself, its paintwork chipped and streaked with rust, its visor cracked and yellowed with age. Although I had never seen one in the flesh before, I recognised it immediately, and closer inspection confirmed its origin. In raised lettering on the breastplate were the words:
Unlike some helmets of similar vintage which required heavy lead weights to sink them, the Snead helmet was made of cast iron and sank under its own weight. That 27kg also happens to be one of the tests of authenticity, which this particular one passed. Three days later, after dipping into my savings, the helmet was mine.
After many weeks of careful renovation it was ready for its first dive, but lacked a suitable air pump. Original hand-pumps in full working order are scarce and generally too expensive to merit serious consideration, and I was casting around for an alternative when Peter Bernardes, then working at Fort Bovisand, came up with the answer: a surface supply panel.
His suggestion was that two aqualung cylinders could supply compressed air to a control panel, which in turn would supply a precisely controlled flow of air to the helmet according to its depth. In effect the panel would be a "superpump", capable of delivering air for as long as the surface attendant could keep it supplied with freshly charged cylinders. As an added safety measure a new non-return valve in the helmet would guard against any mishaps when changing cylinders.
It was a simple idea, less expensive and much more reliable than a hand-pump. I agreed at once and Peter built it for me, smart brass-bound box and all.
The first trials took place in a 6m diving tank at Devonport Dockyard, courtesy of the Royal Navy. All went well, and once we had mastered the tricks of the trade we were ready to take the helmet to sea.
From the diver's point of view, any initial feeling of discomfort or claustrophobia (a common reaction to the helmet) disappears as soon as you leave the surface. Twenty-seven kilograms reduce to an untroublesome 2kg, while air flows sweetly through the helmet to escape around the skirt in a continuous stream of noisy bubbles.
The golden rule of open-helmet diving is learnt within minutes of submerging: stay upright. As long as you do so the helmet behaves admirably, sitting lightly on the shoulders and keeping the water level comfortably under your chin.
Bending forward, even a little, invites trouble. When a certain critical point is reached, the helmet suddenly topples forward, releasing its air and clouting you on the back of the head for good measure. It's a mistake you make only once. Thereafter, the golden rule comes naturally.
After that, there's only a little left to learn. Descents and ascents on a shotline in a wobbly helmet call for concentration; ear-clearing calls for mastery of the nose-clip; and rope signals call for patience at both ends. The rest is plain sailing. . .
At 13m the wreck of the Abelard would probably have been just within gasping range of the helmet's original hand-pump, but when I touched bottom the air supply from the panel was plentiful and unfaltering. I was able to wander comfortably around the site to the limit of my hose, which in turn guided me back to the shotline at the end of the dive.
As a result of this and many other dives, my confidence in the system is complete, though not to the extent of dispensing with the services of a safety diver. When you're standing up to your chin in water and breathing from a wobbly bubble, 13m is a long way down.
And the history of the helmet? Unfortunately, little is known about the Snead Company of Jersey City, except that it produced fine diving helmets for some years from the early 1900s to about 1940, after which it went quietly out of business.
Although it would be good to know when my helmet was last dived, and by whom, perhaps the most important fact is the obvious one. It's now back in serviceable order and being dived again at sea.
Appeared in DIVER - November 1999.