March 21, 1 9 1 8 
Land & Water 
9 
world are merchant ships ever allowed to go out alone ? 
The answer is simple : We have not enough destroyers to 
provide escorts for all. If we had, the submarine war would 
now be of the past. Another reason — and it points out the 
convoy system's chief fault — free ships make faster time, 
and, accordingly, can move more goods than when they are 
grouped in convoys. Tonnage, or carrying capacity (which 
amounts to the same thing), is reduced ; first, by delays 
waiting for escorts ; second, by limiting the speed of the 
faster ships. The ship on which I recently came from New 
York to Liverpool, ior instance, is a seven-day boat. Two 
others in our convoy — vessels of enormous tonnage — were 
equally fast : yet, by being forced to take the speed of the 
slowest vessel, these fast ships took so many days to cross 
that it almost sufficed for them to have made the return 
\"oyage to New York. 
In spite of this manifest fault, the convoy system is here 
to stay ; for it is wholly impossible to maintain, safe routes 
with merchant shipping scattered all over the world. To 
control its passage and to divert it in accordance with enemy 
movements, it must be grouped under war vessels. The 
great reduction in mercantile sinkings more than makes up 
for delays and low speed. It should not be 'forgotten that 
after a convoy passes through the danger zone its units 
are usually permitted to go on alone. So the speed limita- 
tion apphes only for a couple of days. Summing up the 
convoy system, it is safe to say that shipping interests will 
be best served by extending it, as fast as possible, till it 
covers all vessels. A step was taken in this direction 
when, the other day, an Order in Council was passed 
prohibiting vessels from leaving British ports without a 
licence. 
The limitations and advantages of convoys being thus 
defined, let us briefly examine those of the submarine. 
Instead of being free as the fish, they operate within quite 
narrow lines while exposed to special risks. Think of the 
uncharted rocks that must reach up into the underseas 
lanes along which the U-boat blunders like a blind fish ; the 
mine-fields, "floaters," treacherous tides, traps, decoys, nets, 
that turn submarine navigation into one long blind hazard. 
I heard of one U-boat that blundered into the Maelstrom, 
the famous whirlpool ofi the coast of Norway, chosen by 
Jules Verne to kill off Captain Nemo and his Nautilus. Then 
think of the special war risks — the "blimps" and hydroplanes 
dropping bombs from the sky ; the httle P-boats, always 
ready to engage in one of those desperate sea duels where 
no quarter is given or asked ; finally, the destroyer, 
a foe so deadly that the Germans have talked long and 
loudly of "underwater battle-cruisers" to drive it off the 
seas. 
Most of this talk was meant for foreign consumption, for 
the German naval constructors are quite aware of certain 
limitations that make against such a boat. Add armour to 
a U-boat, and her size must be increased to provide more 
buoyancy. Increased bulk calls for heavier internal struc- 
ture, heavier engines, heavier gun platforms for bigger guns ; 
larger quarters for a more numerous crew ; larger fuel and 
ballast tanks ; all of which calls for more buoyancy, that is, 
size ; which, again, calls for more armour plate. 
Such a vessel would present a deeper target for a torpedo 
than any destroyer ; and whereas she might drop twenty 
shells on the latter without putting her out of commission, 
one well-planted shot would send her to the bottom. She 
would stand but a poor chance in a stand-up fight with the 
half-dozen destroyers that are to be found with almost any 
convoy. She would require, moreover, such deep water for 
her manoeuvring that she could hardly operate in the shoals 
and shallows around the British Isles, where her prey would 
be principally found. Lastly, she could chase only one 
vessel at a time. As two years have passed since we first 
heard this "undersea battle-cruiser" talk, we can rest assured 
that after balancing the cost in time, labour, money, and 
materials, against possible advantages, the German naval 
constructors have pronounced against them. 
There are also decided limitations in submarine operation. 
It cannot emerge and dive, 'as is generally believed, with 
porpoise ease. If they go down at an angle of more than 
12 degrees, the older types capsize their ballast tanks and 
become helpless hulks. Abrupt dives, too, are very dan- 
gerous. One commander told me how his hair stood on 
end when, on a quick dive, his vessel went down and down 
and down, and he thought he would never be able to stop 
her. No doubt many a U-boat has nose-divod into the deeps, 
where her steel sides were crushed like a thin egg-shell. Once 
on the surface, it takes some minutes for a submarine to 
submerge ; and if she be seen by a destroyer, a depth-mine 
dropped at the head of the tell-tale wake is very likely to 
Neither can a U-boat cruise indefinitely under water. 
Seventy miles is about the limit — at any speed. After that, 
it must recharge its batteries while steaming on the surface, 
and if it be caught with exhausted batteries, its situation 
is more than precarious. There is a case on record, indeed, 
of three Germem submarines that lay for forty-eight hours 
on the bottom, listening to the screws of the patrol chugging 
above. Two that tried to sneak away in the night were 
sunk. The third surrendered. 
Surface cruising has also its limits, being dependent on 
fuel. On the average, a U-boat can stay out about twenty 
or twenty-five days ; but a considerable part of this time is 
used up coming from and going back to the base, and many 
attempts have been made to extend it by the establishment 
of fuel bases. One ingenious commander used to cache 
barrels of fuel, oil, and petrol, loot from c^tured tankers, 
at the bottom of a sheltered cove. But ah oil spot betrayed 
him one day to a British destroyer. 
The usual procedure would have been to carry the barrels 
off. But, with a flash of genius, the British commander, 
so the story is told, removed the bungs, poured a few gallons 
of picric acid — a powerful explosive — into each barrel, 
resunk them, and sailed away. It requires but a small 
effort of the imagination to picture what happened to the 
U-boat when it began to use that petrol. 
A Submarine's Dangers 
Neither does the submarine have things all its own way 
in duels with merchant vessels. Indeed, it fights at a dis- 
advantage, for whereas a dozen shells may fail to stop a 
fleeing vessel, one well-planted hit will send the U-boat to 
the bottom. Though German torpedoes have an effective 
range of 7,000 yards, shooting is uncertain at long distances.' 
The U-boat usually tries to get within 2,000 yards, and this, 
especially in shots at a convoy, endangers it getting away. 
Rough weather also brings a pause in the hunting, for the 
periscope describes a far wider arc than the hull, which 
threshes around like a wounded whale in a seaway, making 
both observation and the sighting of shots impossible. In 
such weather, the U-boats lie on the bottom in some sheltered 
cove. During the ektremely bad weather last November, 
indeed, the U-boat bag fell from eighteen large ships to six 
in the first week, to one in the second. 
All of these dangers and difficulties of the underseas 
campaign are increased by the reports of U-boat movements 
sent out from observation stations on land and ships at sea. 
When cruising with the American destroyer fleet, I was 
astonished by the number and accuracy of those that came 
in a constant stream to the bridge. Position and course 
were always given, so, besides drawing the patrols and 
seaplanes after them, merchant ships could easily avoid 
their locality. The reports accounted for a despairing note 
in a wireless message we picked up, one evening, in transit 
between two U-boats. 
" Have you seen any ships to-day ? The ocean seems 
empty." 
This commander's report was one of those, no doubt, on 
which the German Adrniralty based its explanation for the 
decrease in the U-boat weekly bag : "Enemy shipping is so 
depleted by the attacks of our invincible U-boats that it is 
becoming more and more difficult to find ships to sink " : 
this during a week that had seen nearly five thousand ships 
sail in and out of British ports alone ! And probably half 
as many more from Allied harbours. 
Summing the U-boat's capacities and potentialities, we 
see that instead of being the original sea-devil, if is really a 
hunted creature — hunted so successfully, moreover, that 
from 40 to 50 per cent, were sunk last year. This great loss 
was aggravated by that of the torpedoes, which take time 
and money to make. Indeed, the yearly output of the 
United States Torpedo Works before the war was only 
twelve. The smaller U-boats carry ten each ; the larger 
and later types, twenty. Accordingly, if one be sunk out- 
ward bound, which happens quite often, the loss of the 
torpedoes is greater than that of the vessel. It is highly 
improbable that any U-boat goes down without carrying 
some torpedoes with her. It is also comforting to know that 
five or six are shot away for every merchant vessel sunk. 
The weekly bag costs the German Government over a hundred 
thousand poinds in torpedoes alone. 
The outlook for the U-boat is bad. The life of a sub- 
marine commander has never been what one could call a 
good insurance risk. In 1917 he made two voyages and a 
half before, quite literally, he went down and out. From 
present indications — there are a few things in store for him 
that I know of, but cannot tell — his life during 1918 will 
