17th April 1917: On route from Le Havre and carrying their wounded to Southampton the Hospital Ships ‘Lanfranc’ and ‘Donegal’ were torpedoed, both sinking rapidly and with the loss of 40 men on each ship. At the time the HS ‘Lanfranc’ (photograph right) had 387 patients on board including 167 wounded German soldiers, of which 18 drowned.
16th April 1917: The Second Battle of the Aisne began as part of the ‘Nivelle Offensive’. After a week of diversionary attacks by the British to the north at Arras, 19 Divisions of the French Fifth and Sixth Armies went into battle along an 80 km front from Soissons to Reims. Losses were horrendous and by the end the French had suffered 187,000 casualties, triggering mutinies within the French Army and the replacing of Nivelle by General Petain.
10th April 1917: While returning to pick up wounded at the port of Le Havre, France, the Hospital Ship HMHS Salta struck a mine at 11:43, one mile (1.6 km) north of the entrance to the dam. A huge explosion smashed the hull near the stern in the engine room and hold number three. Water rushed into the disabled ship which listed to starboard and sank in less than 10 minutes. Of the 205 passengers and crew members, nine nurses, 42 member of the Royal Army Medical Corps (RAMC) and 79 crew drowned. The British patrol boat HMS P-26 attempted to come alongside to assist, but also struck a mine and sank.
9th April 1917: At dawn the British First and Third Armies launched their great offensive at Vimy and Arras respectively. It had been prepared by a massive artillery bombardment greater than that at the Somme, and the infantry advanced more effectively under a creeping barrage. The attack succeeded in most of the areas and at Arras success was almost complete, taking the first two defensive systems. For the Canadians at Vimy Ridge this was the first time their four divisions fought together as a unified force and despite heavy losses this victorious day would be seen as key in their evolution from dominion to an independent nation.
6th April 1917: The United States declares war on Germany.
On 2nd April 1917, President Woodrow Wilson went before a joint session of Congress to request a declaration of war against Germany. Wilson cited Germany’s violation of its pledge to suspend unrestricted submarine warfare in the North Atlantic and the Mediterranean, as well as its attempts to entice Mexico into an alliance against the United States, as his reasons for declaring war. On April 4, 1917, the U.S. Senate voted in support of the measure to declare war on Germany. The House concurred two days later. Although 14,000 US infantry landed in France on 26th June 1917 to begin training, it would take at least 12 months before US troops were present on the Western Front in enough numbers to have any effect on the outcome of the war.
31st March 1917: The Gloucester Castle was a steam ship requisitioned by the British for use as a hospital ship during the First World War, operating in the Mediterranean between Lemnos and Malta and taking the wounded back across the English Channel from the Western Front. On one such voyage from Le Havre to Southampton on 31st March 1917 when carrying 399 patients including 300 cot cases, she was torpedoed by German U-boat U-32 off the Isle of Wight. All the patients were evacuated by the attendant destroyers and other transports, but three unfortunately died during the transfer. Although badly damaged she was eventually towed into port.
20th March 1917: In February 1915 the HMHS Asturias was hit by a torpedo but it failed to explode. However on 20th March 1917, not long after the resumption of the German announcement of unrestricted submarine warfare against shipping deemed to be supporting the Allied war effort, after landing 1,000 wounded at Avonmouth in the Bristol Channel, the Asturias was attacked by German submarine off the south Devon coast and struck by a torpedo which blew off her stern, killing 35 of her crew. The Captain of U20 which sank the Asturias was Capitanleutnant Walther Schweiger, who two years before had been in command of the U-Boat which sank the Lusitania. She was able to be beached near Bolt Head but her damage was so extensive that she was declared a total loss. However her hulk was put to use as a floating ammunition store at Plymouth for the rest of the war.
23rd February 1917: The great German withdrawal begins. They evacuate Serre, Miraumont, Petit Miraumont, Pys and (facing the I Anzac Corps) Warlencourt near Bapaume, falling back 25 miles to establish stronger positions along the Hindenburg Line. The shorter defensive position behind the Noyon Salient was built to economise on manpower, contain an Allied breakthrough and make possible a deliberate withdrawal to prepared positions utilising strong-points and protected by thick wire entanglements. By destroying the infrastructure and demolishing civilian buildings in the salient before a withdrawal, the Germans could dislocate Franco-British offensive preparations, by forcing
them to advance into a wasteland. The British and French armies would need about eight weeks to rebuild roads, bridges and railways in the abandoned area before they could attack. A shorter Western Front could be held with fewer troops and by incorporating the lessons of defensive battle on the Somme, the importance of troop dispersal, reverse-slope positions, defence in depth and camouflage, German infantry casualties could be reduced. While the German army recuperated from the losses of 1916, protected by the Hindenburg Line and similar defensive positions on the rest of the Western Front, a return to unrestricted submarine warfare and a strategic bombing offensive against Britain were planned.
3rd February 1917: The United States severs diplomatic relations with Germany as U-Boats threaten US shipping. Intercepted messages reveal that Germany is provoking the Mexicans into war against the US.
31st January 1917: Germany warns neutrals of unrestricted submarine warfare. The German Government issued its warning to neutrals that from 1st February the waters around Great Britain, France and Italy were to be considered a barred zone, in which merchant vessels would be liable to be sunk without notice.