The curtain raiser at the 12 September lecture meeting was given by the society's former chairman Hamish Paterson, who stood in at short notice for Allan Sinclair. His subject was the defence of the Oslo Fjord during the German invasion of Norway in April 1940.
The confrontation between the Norwegian coastal Artillery and the German Navy that took place in the early hours of 9April 1940 had its origins in the Russo-Finnish War of 1939-40, and the intention of Britain and France to aid the Finns by sending troops through Narvik in northern Norway. This could have disrupted the supply of Swedish iron ore to Germany, and it turned Hitler's attention to a possible invasion of that country. The German plan was improvised using tourist maps and Baedeker guide books. The bulk of the invasion force was to be carried by the Kriegsmarine supported by paratroop attacks on the airfields at Oslo and Stavanger. The force that was to seize Oslo was embarked in the pocket battleship Lutzow, the heavy cruiser Blucher, the light cruiser Emden, the gunnery training ship Brummer, three small destroyers and eight minesweepers. They were carrying a total of 2 000 troops.
The defences of Oslo Fjord were commanded by Colonel Birger Eriksen. These consisted of three 28cm guns, four 28cm howitzers, three 15cm guns, two six-pounders and four 24-inch torpedo tubes. His only trained personnel were some officer cadets, and 400 conscripts with less than one week's service. The minefield controlling the entrance to the fjord had not been laid.
Helped by the misty weather the German ships penetrated the fjord without resistance, but not before the alarm had been raised and the lighthouse lights extinguished. Colonel Eriksen prepared his defences at the Oskarsborg fort. At 04h15 a searchlight illuminated the Blucher. The first 28cm round, fired at a range of 1 400m, hit the ship's fire control. The second hit the aircraft hanger. The 15cm guns smashed the bridge. Out of control, the Blucher moved out of the arc of the guns, but right into the trap of the torpedo battery. The torpedoes were ancient, but recently overhauled. One hit the Blucher's torpedo magazine and the other her engine room. She sank at 07h00.
Subsequent gunfire damaged the Brummer and the Lutzow, and forced them to retreat. Their answering fire merely damaged the roof of the fort's barracks. However, in daylight the Luftwaffe took a hand, and Eriksen soon saw his position as hopeless. He surrendered at 09h00 on 10 April, having bought sufficient time for the royal family to escape from Olso to Britain along with the country's gold reserves. He was honourably acquitted at his court martial in 1945, and his statue now stands in the courtyard of the fortress.
The German armament manufacturer, Krupps Steel, has for over a century maintained an international reputation for the size and quality of the guns it produces. However, it surpassed itself when, in anticipation of WW2, it built the largest gun ever made, Heavy Gustav, a monster weighing 1 350t.
Heavy Gustav was the subject of the main lecture of the evening. The speaker was Louis Wildenboer, who explained that the primary purpose of such a massive artillery piece was to smash the steel and concrete fortifications of the French Maginot Line. In 1937 Krupps was commissioned to design a gun able to fire a projectile capable of penetrating 1m of armour plates, 7m of reinforced concrete, and 30m of compacted earth. The range would be 45km, which would put it beyond the reach of retaliatory artillery. Possible targets at that stage were the Maginot Line and the Belgian forts.
After intensive calculations Krupps presented the German Army with its designs, and in 1939 the construction of an 800mm gun in three variants was approved.
SCHWERER GUSTAV (Heavy Gustav) would have a calibre of 800mm with an explosive shell of 5t at 48km range, and an armour-piercing shell of 7t at 39km range.
SCHWERER LANGER GUSTAV (Heavy Long Gustav) would have a calibre of 520mm with a smoothbore attachment firing a finned projectile of 3t to a range of 135km.
LANGER GUSTAV (Long Gustav) with a calibre of 520mm, a smoothbore attachment and firing a rocket-assisted shell of 2t up to a range of over 150km.
The immense size and weight of the gun meant that transport would have to be by rail in prefabricated form with assembly at the firing site. The gun itself straddled two railway tracks, and another two had to be erected alongside to accommodate the cranes needed for assembly. A total of 28 railway wagons were required to transport the gun and its supplies. The track on which the gun ran had to be curved to allow for traversing. The number of soldiers required to operate the gun was 250, but another 1 250 men were needed to erect, service, overhaul and protect the gun, including a team of engineers and scientists tasked with evaluating the performance of every shot.
Progress in building was slow, and by the time the gun was ready for action the Maginot Line was in German hands. The other two variants were dropped, and for a time it looked as if Heavy Gustav itself was redundant. Gibraltar was considered a possible target, but the obduracy of General Franco eventually ruled that out. However, the attack on the Soviet Union brought new opportunities, and the first and final enemy target for Heavy Gustav turned out to be the heavily defended Crimean naval base of Sebastopol.
It required a mere 48 rounds from the giant gun to wreck the defences of Sebastopol and persuade the garrison to surrender. After that the gun was returned to Germany, and although there were plans to use it against Britain, nothing came of them. Heavy Gustav was captured intact by the US Army in 1945. After being photographed it was destroyed.
George Barrell (Scribe) (011) 791-2581
Contact number in Cape Town: John (Jochen) Mahncke (021) 797-5167
Contact number in Durban: Dr Ingrid Machin (031) 201-3983
* NOTE* Fast mirror and backup site BOOKMARK FOR REFERENCE Main site * NOTE*