The menace of German submarines, abated for a while, has broken out again. Now the threat is greater than ever, and our shipping losses have risen. R.A.F. Coastal Command has had a large hand in forcing the U-boats to adopt new devices and commented on here by Capt. JOSEPH HAWKINS, who has spent 40 years at sea.
"You keep your schnorkel out of this!" is a remark that may be heard in any sailors' tavern alongshore any night of the week. Thus Hitler's latest secret weapon, the Schnorkel, has become a salt joke – of sorts. These men who jest with Death, as is the way of all seafarers, know that the Schnorkel device may bring a U-boat within harbour, or enable it to approach unseen up to the side of their ship at sea.
The Schnorkel is a tube or funnel device, fitted aboard a U-boat, enabling the latter to draw down fresh air from the surface and to discharge exhaust gases from the engines and used air from the crew's quarters. By this means the vessel can remain submerged almost indefinitely – invisible form the air and from the decks of ships; it can approach convoys unseen, and perhaps penetrate harbours when the booms are opened fro our ships.
This latest weapon would also enable German designers to plan a craft seaworthy enough to ride winds and waves on the surface as well as glide fish-like in the depths; completely new designs of submarines able to travel fast underwater and to go deeper will certainly be evolved. Submarines up to now have had to surface for an hour or more in every twenty-four, to renew air aboard and recharge the electric batteries used for underwater travel, batteries being necessary because the fumes of Diesel engines could not be tolerated below the surface. But electric motors give only a poor underwater speed – usually 4 or 5 knots. On the surface, Diesels give a speed of over 20 knots. Underwater Diesels, if they could be used, would give, perhaps, half that speed or more, thus doubling the effective underwater speed of a U-boat and enabling it to keep pace with a convoy without ever surfacing and showing itself.
Though the Schnorkel may be an Allied seaman's joke, it is likely to be the death of a good many of them; for it was very largely due to aircraft of Coastal Command and the Fleet Air Arm that the U-boat was beaten earlier in this war, after grievous losses. If aircraft lose their effectiveness almost completely against U-boats that can remain submerged all the time, and yet keep pace underwater with the convoys they are shadowing, the Hun will have a fruitful innings. Hitherto, aircraft forced them under water, and under water meant a speed of no more that 4 or 5 knots, and that was too slow to keep near a convoy.
But that innings, however short it may prove to be, will be packed with discomforts to an extreme degree. For the new Schnorkel U-boats are nightmare to the most hardened Nazi crews; for one thing, the submarine with this new breathing device cannot, whilst on a mission, surface at all. U-boat Command spokesman Heinrich Schwich has said on the German radio, "Not a single man, throughout the cruise, ever has a dry piece of clothing on his body; the crews are subject to a physical and psychological strain for which the term gigantic is not an over-statement."
Again, a Nazi radio commentator has said: "We sometimes live under the water, 'breathing' through the funnel, for as long as ten weeks. The hardships and strain are incomparably greater than ever before. There is hardly a quiet moment, and no chance to come up for fresh air or to smoke. There is no distraction. Lights can be used only for essentials, to save current. The men cannot even listen to the radio. As the days pass, and then weeks, the atmosphere gets more and more humid" ... And, on top of it all, hunted and depth-charged and bombed in this frail underwater vessel that at any moment of day or night may prove the entire crew's grave – what a prospect for Hitler's mariners! They plumb the depths of misery. Another secret weapon boasted of by German prisoners and German radio is the "electric eye" torpedo, a development of the acoustic mine. The torpedo is fitted with a magnetic-electric apparatus which, attracted by the vibration of a ship's engine, turns the torpedo towards the ship out of whatever course it may have been running on, as soon as it comes within a few hundred yards of the hull. Other new devices are the "water-donkey" (decoy craft) and the gyro-plane.
Further, the German propagandists claim to have an "anti-Asdic" apparatus aboard the new U-boats. This seems unlikely, but we have to consider its possibility. The Hun should never have known anything about our Asdic device – that was one of the things that fell into his hands when France collapsed in 1940. From the merchant seaman's point of view France has a long row to hoe before she wipes out the harm which that loss did to our shipping.
I can speak of the bitterness on this point of some of the Masters who are my acquaintances. There have been times when we have not stepped out of our clothes for two months at a time, and hardly slept – just a catnap now and then with the First Officer's elbow in your ribs as soon as you shut your eyes, to fetch you back to the bridge again for some emergency. Some skippers I know have been torpedoed ten times. One ship, the Dan-y-Bryn, once had six "tin fishes" running parallel with her after she had made a sharp turn to port to avoid taking them broadside-on. As many as 30 U-boats have been sighted from the air in a single convoy battle with assembled wolf-packs.
What of the coming days when the 30 raiders will still be there, but invisible beneath the waves, and able to keep pace with us unseen? Well, we still have our 4-in. guns, our 12-pounders and our half-dozen Oerlikons. Aboard the escort vessels they still have the Asdic, and the depth charges, and one or two other surprise packets I am not at liberty to mention. If the enemy have developed a target-seeking torpedo, we shall have to perfect a torpedo-diverting device, or a U-boat-seeking bomb!
Our shipping has been decimated, and our losses of seaman have been very heavy. More than 4,000 of them still languish as prisoners on German soil today. But every sun that rises sees more than 2,000 vessels flying the old Red Duster actually out on the sea-roads of the world, and British seamen alone equal about eight Army divisions, bringing us more than a third of our food, as well as most of the fertilizers that enable British farmers to produce the rest. Not a ship, not a man of them all will be missing from his job, and as for the new U-boats – well, they had better keep their damned Schnorkels out of this!