Historical Diving Society Finland organised its tenth annual Divers day event on 30th of May. As this was a jubilee year, a decision was made to invite the general public to dive river Aura in (a replica of) an 18th century diving bell. Some arrived on purpose, some by accident, but all were welcomed to dive. At least 300 persons paid a visit while almost one hundred persons of all ages dived with the bell.
A bell dive
Our diving bell “Mårten” has been manufactured according to 18th century instructions by swedish Mårten Triewald. A bell like this was used to recover the guns of ship Vasa. Divers in a bell will eventually run out of oxygen. Hence, ventilation is required. Fresh air can be brought down and into the bell by weighted tuns This was however not needed during our short visits.
A diving bell, even though it is made of steel, will not sink unless properly weighted. For this purpose four spherical weights have been cast.
At least 45 bell dives were made, two persons at a time on average, sometimes one, sometimes three. Thus nearly one hundred persons were able to reach the depth of two meters in river Aura. Inside the bell water did not quite rise to the hip. The bell was fitted, thanks to DG-Diving Group, with light and a telephone connection to the surface, which made the atmosphere inside very comfortable. A few bold people bottomed the river at five metres. Our club did dive to -10 metres in May though, and in Sweden dives have been made to -30m.
Hard hat diving
Participants were given the chance to try a diving helmet designed by Augustus Siebe (a 12 bolt helmet and the standard diving dress). A breast plate made of metal is attached to the diving suit using 12 meticulously tightened brass bolts. Every diver used to have their own hankerchief as the suits were common to all workers in a company. We did not use historical 19th century diving suits however but opted for an Ursuit Heavy Light Kevlar BDS. It is faster to don and it is also much more comfortable. We only had time to put four persons into water in standard diving dress as the lift was mostly operating the bell.
When the breast plate is in place and the shoes are on, it’s time to attach the helmet. The front window is left open at this point to allow discussion and (historically) smoking. When it is screwed in before diving, one has to start pumping air into the suit. There is also a valve for exhaust air, which can be operated by the diver by tilting his head to the side. This way, the suit will not swell like a balloon when fresh air is flowing in.
A retired professional diver paid a visit and told us how they had been diving deep, -60 metres, using standard diving dress. No matter how the front window has tightened it always spilled water at greater depths.
Fresh air was pumped by hand, of course. A pump fitted with three cylinders was used. Samaller two cylinder pumps do exist but they reach lower pressures thus limiting diving depth.
A hard hat divers helmet and weigths weigh around 28 kg. All of this bulk rests on ones shoulders. The helmet is lighter in water but on dry land one really wants to support it by hands.
Divers were lowered into an “aquarium” because then people could watch them. A dive in the river would have been more exciting but nobody would have seen it.
A wooden helmet of swedish type
The whole event was once again planned by Jouko Moisala. He dived in the aquarium using a swedish home made wooden helmet. Such a thing has actually been used historically although it deceptively looks like a bird house. A small modern manual air pump was used to deliver fresh air.
You are warmly welcome to join us if you find historical diving equipment or historical diving in general interesting.