Horseshoe route

The Horseshoe Route was a flying boat route between Sydney, Australia, and Durban, South Africa, via Singapore and Cairo during World War II. Mail could then be sent by sea between South Africa and Britain. Using Short Empire C Class S23 and S33 flying boats, British Overseas Airways Corporation (BOAC) operated the section between Durban and Sydney while Qantas Empire Airways operated the section between Singapore and Sydney. In October 1941, Qantas took over the Karachi - Singapore section as BOAC were short of pilots.

This emergency route was necessitated by Italy entering the war in June 1940, which made it impossible for mail to be flown between Britain and Egypt (and thus on to Australia or Africa) via the Mediterranean. The Horseshoe Route to Australia was suspended after the loss of Singapore in February 1942 after which it was restricted to being between Durban and Calcutta.

The Horseshoe run was a ninteeth century Australasian shipping route.

Initial services
The first Durban - Sydney and Sydney - Durban flights both left on 19th June 1940 and arrived at their destination on 1st July. The first mail for the UK was sent from Cape Town on 5th July on the Winchester Castle and arrived in Britain on 21st July. The first mail dispatch from London was on 19th June and was sent on the Arundel Castle which left Southampton on 20th June and arrived in Cape Town on 7th July. It connected with the fourth Horseshoe flight from Durban, leaving there on 10th July and arriving in Sydney on 24th July.

Initially the Horseshoe service was weekly, but in August 1940 its frequency was increased to twice a week.

Disruption in mid 1941
The route was disrupted in late April 1941 due to an uprising in Iraq which meant that the stop at Lake Habbaniyah was not available and there were no flights between Cairo and Basra in early May. A non-stop shuttle service was then set up between Tiberias and Basra, but the mail capacity was greatly reduced as more fuel had to be carried. The frequency of the service between Basra and Singapore was also reduced to once per week. The associated campaign in Syria meant that it was late July 1941 before the route was functioning normally again.

End of through route to Sydney
The entry of Japan into World War II in December 1941 was not unexpected and reserve routes between Rangoon and Batavia had been prepared. Reserve Route 1 avoided Bangkok, but due to the rapid Japanese advance, it was only used once on 8th December and Reserve Route 2 which also avoided Penang was used. It was via Port Blair in the Andaman Islands. After 30th December, Reserve Route 3 was used in which Singapore was also avoided although shuttle flights continued between Batavia and Singapore.

In early February 1942, the Batavia - Darwin (Australia) section was changed from having an overnight stop at Sourabaya to having overnight stops at Tjilatjap and Broome, but the last through service was shortly afterwards in mid-February.

The Horseshoe run
The Horseshoe run by the Union Steamship Company carried passengers and cargo between Australian and New Zealand ports in the late 19th century. Several ships were used from 1882 for about 15 years: the Hauroto, Manapouri, Tarawera, and Wairarapa:
 * Sailing from Port Chalmers, she (the Hauroto) made calls at Lyttelton, Wellington, Napier, Gisborne and Auckland; also at Opua for bunkers (ie coal) en route to Sydney, returning via the same ports to Port Chalmers then continuing on to Bluff, Hobart, and Melbourne, then returning to Port Chalmers. After a few years all the North Island ports except Wellington were omitted.

In the early 1890s there was a battle between the Union Co and Huddart Parker on various Australasian routes including the Melbourne-Hobart route, with undercutting by cheap fares and steamers shadowing each other from port to port.