The invasion - hour by hour
Events concerning the naval intrusion into Oslofjord
Much of the invasion below might seem quite uninteresting. This is so because I had the idea to try to track down all naval movements in Oslofjord during the 9th to 11th April, thus I have gathered a lot of info on minor events, and I havent had heart to cut out anything from the list.
Observe that Norwegian time is used. To get German time add
one hour.
Dates are given as [day #]/[month #], i e the 9th of April is 9/4.
| date | time | end time | event | position |
| 2/4 | The time for Weserübung (the invasion) is fixed to 9th April. | |||
| 3/4 | The first transports leaves German ports. | |||
| 8/4 | 02:00 | Group 5, of the Kriegschiff staffel, sails from the bay of Kiel, with the mission to take the forts and naval bases in Oslofjord, and occupy Oslo. | Kiel | |
| 8/4 | Group 5 is attacked by submarine outside Skagen. No hit | outside Skagen | ||
| 8/4 | 22:20 | Radio messsage from Oslo Radio that all lighthouses shall be turned off, by order from commander in chief of the Navy. The order was however not executed. | ||
| 8/4 | 23:00 | Group 5 and PolIII, a Norwegian patrol vessel at the outer guard line of Oslofjord fortress area, sights each other. The Torpedo Boat (light destroyer) Albatros is dispatched to deal withthe Norwegian vessel. By mistake Pol III rams Albatros. | outer Oslofjord | |
| 8/4 | 23:10 | Coast watch at the Norwegian island Færder reports passing ships to 1.Sjøforsvarsdistr. | Færder | |
| 8/4 | 23:10 | Norwegian patrol vessel Farm, also at the outer guard line of Oslofjord fortress area, sights unidentified ships and sends message | outer Oslofjord | |
| 8/4 | 23:15 | Admiral staff gets the message from Farm | Oslo | |
| 8/4 | 23:15 | Pol III fires larmrocket. Then Pol III ges up side by side with Albatros and there is a short conversation between the commanders. The ships separates again and suddenly Albatros opens fire on Pol III. The commander is wounded, and drowns when the the crew leaves the boat. The first Norwegian causalty of the invasion. | outer Oslofjord | |
| 8/4 | 23:15 | Fog is coming in | Oslofjord | |
| 8/4 | 23:20 | Alarm on Rauøy fort | Rauøy | |
| 8/4 | 23:25 | Norwegian patrol vessel Kjæk sights a ship and fires a rocket | ||
| 8/4 | 23:28 | Rauøy is battle ready. Searchlights are lit. | Rauøy | |
| 8/4 | 23:30 | Rauøy sights two big warships about 4 km west S Misingen | Rauøy | |
| 8/4 | 23:30 | Warning shot with blank round is fired from Rauøy | Rauøy | |
| 8/4 | 23:30 | Alarm on Bolærne | Bolærne | |
| 8/4 | 23:32 | Warning shot with live ammunition is fired in front of the ships, from Rauøy | Rauøy | |
| 8/4 | 23:36 | 23:43 | 4 rounds fire for effect from Søndre batteri on Rauøy, which however falls very short of target. | Rauøy |
| 8/4 | 23:37 | Bolærne is battle ready | Bolærne | |
| 8/4 | 23:40 | Warning shot with blank round is fired from Bolærne | Bolærne | |
| 8/4 | 23:40 | The fog gets denser | Oslofjord | |
| 8/4 | 23:50 | Battle readiness is ordered on Oscarsborg fortress | Oscarsborg | |
| 9/4 | 00:12 | Order to 1.Sjøforsvarsdist. from Commanding Admiral to lay preplanned mine barrage Rauer-Bolærne as soon as possible | Oslo-Horten | |
| 9/4 | 00:30 | 1.Flyavd ordered to evacuate from Horten to Drøbak | Horten | |
| 9/4 | 01:00 | 02:30 | All airplanes in Horten are evacuated to Drøbak | Horten |
| 9/4 | 01:00 | The British marine attachŽ, Adm H Boyes, visits the Chief of Admiral staff in Oslo and is informed that there are no mines in Oslofjord | Oslo | |
| 9/4 | 01:30 | Order about minelaying is recalled by Commanding Admiral as the British fleet is expected | Oslo-Horten | |
| 9/4 | 02:00 | Otra ready to sail | Horten | |
| 9/4 | 02:00 | Alpha arrives to Filtvet to supplement Furu | Filtvet | |
| 9/4 | 02:00 | 90 men from Emden embarked on R20 and R24, with the mission to take Rauøy fort. | Oslofjord | |
| 9/4 | 02:15 | Olaf Tryggvason at position at the entrance to Horten harbour | Horten | |
| 9/4 | 02:30 | Main force of Group.5 continues north with slow speed | Oslofjord | |
| 9/4 | 02:30 | Landing parties are transferred from Emden to minesweepers in the area Horten - Filtvet | Oslofjord | |
| 9/4 | 02:30 | Otra leaves Horten | Horten | |
| 9/4 | 03:00 | 1.Mineleggerdiv (minelayer unit) is loaded with mines and ready | ||
| 9/4 | 03:38 | Filtvet, at the outer end of the narrows leading to Oscarsborg and Oslo, reports that warships are passing | Filtvet | |
| 9/4 | 04:00 | 1.Mineleggerdivision () is ordered to Jersøy | ||
| 9/4 | 04:00 | 1.Submarine division (A2, A3, A4) leaves Teie | Teie | |
| 9/4 | 04:00 | R20 and R24 stops in Engelsviken to find out where they are (they were lost in the fog) | Engelsviken | |
| 9/4 | 04:00 | Report to Rauøy fort that foregin soliders had been in Engelsvik asking about Rauøy fort | Rauøy fort | |
| 9/4 | 04:10 | Otra reports the presence of a destroyer and two minesweepers, and that they are German. This is the first indication of Nationality that the Norwegian command gets. | outside Horten | |
| 9/4 | 04:21 | The main battery of Oscarsborg opens fire on Blücher at a distancce of 1800 m, scoring two hits. The secondary batteries (15 cm) also opens fire, scoring multiple hits. The return fire is unable to make any damage. | Oscarsborg | |
| 9/4 | 04:30 | Rauøy fort asks I.R.1 in Fredrikstad for an infantry company. I.R.1 has no troops available | Rauøy fort | |
| 9/4 | 04:35 | R17 and R27 enters the bay containing Horten harbour. Albatros and Kondor stays outside, north of the inlet. After first assuming it was Norwegian boats and then firing warning rounds, Olaf Tryggvason fires at R17 and hits it when it has reached the quay, setting it on fire. R27 gets into a duel with Rauma, where both boats takes hits, and Rauma has to withdraw. | Horten | |
| 9/4 | 04:54 | Norwegian merchant M/S Sørland is shot on fire by a German minesweeper south of Oscarsborg. The Norwegians thinks the burning ship is a German warship (Brummer). | inner Oslofjord | |
| 9/4 | 05:00 | 1.Mineleggerdivision in position outside Jersøy | ||
| 9/4 | 05:05 | Message about German landing at Vallø. Oter I leaves from Tønsberg for Vallø. |
||
| 9/4 | 05:17 | The depth charges of R17 explodes, killing a few Germans nearby. | Horten | |
| 9/4 | 05:20 | The Norwegian patrol crafts Treff and Ramoen leaves Kjøbmannskjer (at Vrengen) | Kjøbmannskjer | |
| 9/4 | 05:30 | The magazine for 10.5cm ammunition at Blücher explodes, dooming the ship. | north Oscarsborg | |
| 9/4 | ca 5:30 | R20 lands troops a bit north of N. battery on Rauøy (ca 900 m) | Rauøy fort | |
| 9/4 | 05:50 | Oter I and Skudd I sights R22 and R23 at Torgersøygapet. There is a short firefight, but neither side scores any hits. | ||
| 9/4 | 06:00 | Order to leave Blücher. | ||
| 9/4 | 06:00 | 1.Mineleggerdivision leaves Jersøy without laying any mines. It is considered futile to attempt it with the strong German pesence. They go toward Melsomvik | ||
| 9/4 | 06:00 | Lützow and Albatros begins to land their troops at Son north of Moss. Some troops are landed in Moss too. | Son | |
| 9/4 | 06:15 | Defensive line formed by misc. Norwegian troops. holds the Germans until cease-fire at 08:00. | Rauøy fort | |
| 9/4 | 06:22 | Blücher sinks. | north Oscarsborg | |
| 9/4 | 06:30 | New attempt by a German destroyer to enter Horten harbour is beaten back by Olaf Tryggvason | Horten | |
| 9/4 | before 07:00 | A German delegation arrives to Karljohansvern, the naval base at Horten and HQ of 1.Sjøforsvarsavsnittet. | Horten | |
| 9/4 | 07:00 | Emden and Lützow is sighted outside Horten. Probably only Emden was there though. | Horten | |
| 9/4 | 07:20 | Skoleesk. of the cavalry school in Oslo is ordered to the south end of Bunnefjord to block the road from Son and Moss to Oslo. | Oslo | |
| 9/4 | 07:35 | Norw. Admiral Smith Johansen, commander of 1.Sjøforsvarsavsnittet signs the capitulation of Karljohansvern. | Horten | |
| 9/4 | 08:00 | Order about cease-fire from Sjøforsvarsavsnittet to Rauøy | Rauøy fort | |
| 9/4 | 08:10 | 4. Gardeskp. leaves their barraks for Digerud with the order to disarm the survivors from Blücher. | Oslo | |
| 9/4 | 12:00 | Areal bombing of Oscarsborg pauses while Lützow takes the fort under fire from a distance of 16-17000m. | Oscarsborg | |
| 9/4 | 13:00 | Bombing of Oscarsborg is resumed. The anti aircraft artillery is silenced. The bombing is directed mainly at Söndre (south) Kaholmen. There are no losses due to the bombing but the morale wavers. The communication link between Kaholmen, with the HQ and the main battery, and the mainland with the Kopås battery, is broken. | Oscarsborg | |
| 9/4 | 16:30 | The bombing of Oscarsborg decreases and German ships approaches, but stops at 9000m (Halvorshamn). The Kopås battery is manned, but not the main battery as the crews are dispersed and demoralized. The commander discusses the apearant futility of further resistance with his subordinates. | Oscarsborg | |
| 9/4 | 17:15 | Order from the commander at Oscarsborg to the Kopås battery not to open fire without explicit order. The order is given with optical signals due to the broken telephone link. | Oscarsborg | |
| 9/4 | 18:00 | The bombing of Oscarsborg ceases. A German torpedo boat (Kondor) and a couple of smaller boats are observed as the begin to land troops in Dröbak (at Tollbodbrygga). The Kopås battery is silent due to the previous order. | Oscarsborg | |
| 9/4 | 18:15 | The Husvik battery informs the Kopås battery that they are occupied by Germans. | Oscarsborg | |
| 9/4 | 18:25 | The Kopås battery informs Kaholmen that they are occupied. Kondor approaches Kaholmen with parlimentary flag. | Oscarsborg | |
| 9/4 | 18:30 | Surrender negotiations are initiated on Kondor, and later on Kaholmen. During the night Kondor and a raumboot (minesweeper) passes Oscarsborg, to pick up survivors from Blücher. Oscarsborg is still not occupied and there is no formal surrender, but the commander has given his word of honor that the ships wont be fired upon. | Oscarsborg | |
| 10/4 | 07:20 | Bolærne fires three warning shot against transport ship coming from south, the ship turns south | Bolærne | |
| 10/4 | ca 7.30 | ??? | Bolærne is bombed. No damage. | Bolærne |
| 10/4 | 09:00 | Surreder of Oscarsborg is agreed upon. The German flag is raised. Due to the unusual agreement the Norwegian flag will still be raised also, and Norwegian officers will keep their arms. Lützow and Emden passes | Oscarsborg | |
| 10/4 | 10:45 | Lützow and Emden reaches Oslo | Oslo | |
| 10/4 | Albatross and two armed trawlers approach Bolærne from north. Bolærne opens fire at 8000 m (10-12 shot, no hits) and the Germans turn north. The Norwegian guns are damaged though, due to erronous handling. | Bolærne | ||
| 10/4 | Albatross runs aground (and is not possible to save) | Bolærne | ||
| 10/4 | all morning | Bolærne is bombed and strafed repeatedly. One killed, no damage on batteries. White flag is raised on Bolærne by demoralized privates | Bolærne | |
| 10/4 | Weapon smith reports that only one of the 15cm guns is in (limited) working condition. | Bolærne | ||
| 10/4 | Commander of Bolærne, Maj Færden, decides to make no opposition against any German approach. The white flag is left raised. | Bolærne | ||
| 10/4 | afternoon | Rau 7 (armed whaler) approaches Bolærne | Bolærne | |
| 10/4 | 20:00 | Formal surrender of Bolærne | Bolærne | |
| 10/4 | 21:00 | Norwegian garrision on Bolærne (200 men) loaded on Rau 7 | Bolærne | |
| 10/4 | ca 21.10 | Rau 7 runs aground in Kongshavnsund | ||
| 11/4 | morning | Rau 7 gets free | ||
| 11/4 | 13:30 | Rau 7 reach Horten |