to the Menai Strait - 2 hours with the tide and 5 hrs against it - the tow averaged 7 knots over the ground - and without applying anything like the power the would have been applying that day in the Swellies), and he believes the stream that violent day did not exceed 4 knots.
Dr. Toby Sherwin replies:- "In Simpson et al. page 252 there is a formula which reads:
U = -11.2 - 0.057W 2 cos D - 3.67(R - 3.6)cm s -1
which expresses the enhancement of the flow due to the Residual at Plas Newydd. If we ignore the effect of direction (the cos D), with a northwesterly wind the Southwest Residual could increase by 0.057 x (wind speed) 2. Thus the effect of the 16 m s -1 wind that day would be to add to the immediate strength of the southwest-going stream as much as an extra 15 cm s -1, or 3 knots at Plas Newydd, and quite obviously by a lot more than this in the narrow sections of the Swellies."
Quite clearly the ship was lost because she was too late for the tide. Her loss certainly epitomises the perils of going against all local advice by attempting the outward tow against 'The Ebb' on a big tide. So the focus of the questioning is why was the ship conciously delayed until 0920? Apart from underlining the word "timing", the Sub-Committee Report manages to avoid any mention of this highly critical issue. That the Committee associated the "stormy conditions prevailing at sea" with "a strong undercurrent which is known to occur in the channel" shows them to have been perfectly well aware of what had actually happened. But the Sub-Committee's task was to write a report for a critical audience (which included the Admiralty), so stating that the transit was made even before (by five minutes) the time recommended by the Caernarvon Harbourmaster gave it an outward authoritative respectability which it lacked in practical conviction. Is it at all likely that this was the reason the ship was so tragically delayed? But elsewhere on the Web it is even suggested that the error made was it was not five minutes which should have been deducted but ten, so making the passage five minutes sooner. So even to this day this farcical comedy with "the timing" still continues.
The only explanation for so late a transit is to be found in the Sept. 1953 'Cadet' Editorial, which gives two reasons: "firstly that no ship is as controllable with a following tide as with a head tide". This is certainly true of a ship under her own helm and engine, but Conway was a totally dead tow with both tugs stern-on to the ship. To such a rig, not only was it a matter of complete indifference which way the tide was running, but going through with the tide behind her would have freed both tugs to concentrate entirely on controlling the ship while leaving the tide to provide the motive power. Any effort needed by the stern tug to check the ship's progress would have been fractional compared with the effort required of the head tug in electing to delay the ship to ensure she made (at least) part of the transit against the tide. So their first reason simply doesn't stand up.
Their second reason was: "it was necessary to have as much water in the channel as possible before attempting the passage", and here we are probably getting closer to the truth. Was it believed that there was insufficient water for the ship to be able to follow the local advice? Did they believe that the ship's draft left her no choice but to delay the transit and take her chances with 'The Ebb'? But this keynote issue of the depth of the water is yet another matter which the Sub-Committee Report manages to avoid mentioning. I'm told that the Admiralty (whose property the ship was) at first refused permission to take the ship through to Plas Newydd. (perhaps someone can enlighten me further?) But having been granted that permission and taken the ship through, there could be no reference to anything which might suggest that even on the highest tide of the year the ship might not have had the water until it was too late on the tide to bring her back.
The most authoritative source of information we have about the depth of the water is what we believe to be Captain Goddard's Chart. This chart is (or has been) framed on the wall of the little Caernarvon harbour office. Capt. G D Pari-Huws: "This chart is undated, neither does it bear the name of its surveyor, but is the largest scale chart known to the Caernarvon Harbour Trust and is thought to be from a survey conducted in the 1940's. It has a hydrographic peculiarity in that the underlined sounding figures indicate not the drying heights at Low Water, but the depths at High Water. But why would anyone not lay claim on such excellent work by putting his name to it in the usual way?"