1. War at Sea

2. Naval Power
Before WWI, Britain was considered to be the ultimate naval power
Germany also wanted a huge navy
this led to a naval race (arms build up)
The German strategy was to “choke off” supplies from entering or leaving Britain
This led Germany to use U-boats (submarines)

3. U-Boats Short form of Unterseeboot (undersea boat)
Could be an efficient fleet weapon against enemy naval warships.
Most effectively used as a naval blockade for convoys bringing supplies to enemy areas.

4. Fig 1 – Blockading Germany and supply lines to Britain.

5. British Strategy British strategy was to blockade Germany
Blockade was very successful, as many German supplies began to run out
Germany declared “unrestricted submarine warfare"

6. The U-boat campaign: restricted submarine warfare
Germany made very effective use of its small U-boat fleet (only 23 at the start of the war).
At first, the Germans stuck to the rules of war by sinking only merchant ships belonging to Britain and her allies.
This resulted in a small number of sinking's: only ten by Feb
After Feb the Kaiser ordered a change of tactic.

7. Un-restricted submarine warfare, Feb-Oct 1915
From Feb the Germans declared that any ship in British waters (even neutral ones) would be attacked – this was unrestricted submarine warfare
Sinking's shot up – in August 1915 alone, U-boats sank 42 merchant ships.
One of their victims was the British passenger, the Lusitania, torpedoed in May, Among the 1200 civilian dead were 128 Americans
The sinking was a public relations disaster for the Germans and US opinion was outraged.
After the war, it became known that the Lusitania was carrying munitions for Britain – a breach of the rules of war

8. Blockades & Convoys
To counter the German submarines, the Allies moved shipping into convoys (to accompany for protection)
Ships were guarded by destroyers (smaller, faster, battleships)
Blockades (an obstruction of passage; often surrounding areas to prevent movement) and minefields were laid
Aircraft patrols also monitored the U-boat bases

10. Convoy system
In response to the damage wrought on Allied shipping by the German campaign of 'unrestricted submarine warfare', the Royal Navy introduced a convoy system in June 1917.
As the photograph on the next slide illustrates, it worked by providing escort vessels for individual ships.
These escorts not only guarded against surface gunfire attacks, but also dropped depth charges in areas where German 'U-boats' were known to operate.
The convoy system resulted in a rapid decrease in German attacks on Allied shipping during the last 17 months of the war.

14. Depth charges
exploding

17. Canada’s Contribution
•Canada supplied many ships to the British during WWI
•Enlistment in the Royal Canadian Navy increased

18. Halifax Explosion
The Mont Blanc, carrying 200 tonnes of TNT, entered the Halifax harbour on December 6, 1917
At the same time as the Mont Blanc sailed in, a second ship – the Imo - prepared to leave port and head to the open ocean
Through a series of mixed signals, a collision took place right next to one of the busiest wharves in Halifax.
At 09:05 the Mont Blanc exploded. It was the largest man-made explosion until the atomic bomb in 1945, causing a mini-tidal wave to fan out from the spot of the explosions
The explosion could be heard up to 300 miles away

19. Halifax Explosion

20. Deaths: over 1600 men, women and children killed Injuries: 9000 people
Buildings Destroyed: 1630
Buildings Damaged: 25,000
Help came from all over the world totaling about $30 million

22. "My Grandfather used to walk along the shore in the mornings
"My Grandfather used to walk along the shore in the mornings.“ My grandfather was down on the shore when the explosion occurred. The concussion of the explosion threw him up against rocks on the shore.
Fortunately, he was able to scramble up the rocks before the tsunami hit the Dartmouth shore. The harbour parted, the wave went right over him, but he hung to a lamp post, a great big post along the railway track. He hung on for dear life around that post. Then the wave receded, but just when he got his breath, it came back and went over his head again. The third wave was just to his waist, and then it gradually receded. This all occurred just where the old North Ferry used to be at the foot of Jameson Street.

24. An anchor beam from the Mont Blanc weighing 1140lb and flew 2.3 miles
Over 10% of the population of Halifax was homeless after the explosion. Most of these were working class people. Why do you think these people suffered the worst from the destruction?
/watch?v=MPrGL9Xt-ds (22:00)
Halifax Explosion