The standards, devised by the Bulkhead Committee set up by the British government, were a milestone in passenger ship safety. Had they not been relaxed, the Estonia might have survived the atrocious weather she encountered in a notorious stretch of water.
Human error and an attempt by the captain to arrive in Stockholm on time may have contributed to the disaster. The ship was driven into mountainous seas for five-and-a-half hours before she sank, and some marine safety experts believe that she was travelling at excessive speed for the conditions. Swedish experts have calculated that the 15,500-ton Estonia was doing 15 to 18 knots, double the advisable speed, when she was crippled.
The Gulf of Finland is only 35 miles wide between Estonia and Finland, leaving large vessels little room for error. It has been known to mariners down the ages as 'the ships' graveyard'. Arthur Ransome of Swallows and Amazons fame wrote of seeing a Russian battleship marooned on shoals in the area in his 1923 book, Racundra's First Cruise.
The shallow bottom means that steep seas build up and waves double in frequency and height. Once hit by a wave, a vessel has no time to ride it out before being pounded by the next. Waves of 20ft and more are believed to have pounded the Estonia's bow 'visor', forcing water into the hold and destabilising the ship, something that ferry owners maintain cannot happen.
The seas the Estonia encountered are unlike anything experienced by ferries in British waters. At least three hitherto unreported incidents have occurred in recent years, in which ferries suffered damage to their bow doors. The captains had to go immediately astern and bear away from the waves to avoid capsizing.
Before roll-on roll-off vessels, water in the hold did not have such dramatic consequences for safety, because watertight walls, or bulkheads, had to be fitted in the cargo area.
'As proof of the adequacy of these (earlier) arrangements I recall the Duke of York ferry which was cut in two forward of the bridge, but which floated and survived due to its watertight bulkheads,' writes Gordon Victory, former engineer surveyor-in-chief of the Department of Trade and Industry, in a letter to the Journal of the Institute of Marine Engineers. He says that, 'more importantly, there were no casualties'. The Solas standards ensured that grave damage could be sustained by a ship without the prospect of immediate flooding and capsize. Although upgraded many times since 1929, they were tampered with in 1967 at the insistence of ferry companies, then experiencing a boom thanks to the development of roll-on roll-off vessels. 'Some weasel words were included,' which compromised passenger safety, according to Mr Victory.
The standards were amended so that whenever the subdivision of a ship's cargo deck was incompatible with the use of the ship - as is the case with all roll-on roll-off ferries - there could be alternative arrangements 'which would provide equivalent protection'.
'This,' Mr Victory says, 'has led to the complete negation of good subdivision arrangements in such ships in the interest of commercial considerations, maximising the usage of all spaces and ensuring a quick turnaround.'
Mr Victory calls for the introduction of modern retractable bulkheads in existing ferries. He says there is 'no substitute' for them if disasters such as those that befell the Estonia and Herald of Free Enterprise are to be avoided.
In Mr Victory's view, 'watertight transverse bulkheads, which could be retractable in port, are the logical solution to providing a reasonable degree of damage stability.'
He says large drainage ducts should be provided, connected to the largest saltwater pump on the ship. Crucially, he points out that the so-called Solas 1990 safety standards, negotiated through the International Maritime Organisation and which became operative yesterday, provide for waves up to 1.5m high (the Estonia was in 6m waves when she sank).
'Have they never been to sea?' Mr Victory asks of the officials who negotiated the standards. 'This wave height is almost a calm sea.' He said retractable watertight bulkheads have not been stipulated because commercial factors have outweighed passenger safety.
(Photographs and table omitted)
Leading article, page 22