This was a US operation by an Office of Strategic Services operational group under the command of Major William Colby to help local resistance groups in delaying German withdrawals by attacking the railway to the south of Grong in the county of Trøndelag in German-occupied Norway (24 March/14 June 1945).
Late in the summer of 1943 the 99th Mountain Battalion arrived at Area F (previously Congressional Country Club) for operational group training, with only a relatively small number of the men to be selected for the final Norwegian Operational Group. The battalion, which had been stationed and trained at Camp Hale in Colorado, had been recruited as a unit to form the Norwegian Operational Group. In December 1943 the Norwegian Operational Group of about 100 officers and non-commissioned officers was transferred to the UK, where the men were attached to the OSS Special Operations Headquarters, Scandinavian Section. In anticipation of operations in Norway, the unit then underwent additional training in Scotland.
By the summer of 1944 there were no approved missions in Norway, so the Norwegian Operational Group was committed to operations in France and became the major component of the UK-to-France unit of the French Operational Group.
After the liberation of France, in December 1944 all operational group personnel who had served in France were re-screened for possible assignment to groups destined to fight in other countries or returned to standard military units. Some of those who were reassigned returned to the USA for home leave and further training before assignment to Far Eastern operations; some were transferred to Italian Operational Group operations; and about 50 men of the original Norwegian Operational Group were re-screened to meet tentative plans for operations in Norway.
At the time there was a German garrison of about 150,000 men in the area of Narvik and Tromsø in northern Norway, and intelligence information indicated that these were to be transferred to the south through Norway for service in the defence of Germany.
The only available routes available to the Germans for the movement of these men were roads which were currently closed by snow, the sea and the single-track Nordland railway running to a southern terminus at Trondheim. The Supreme Headquarters Allied Expeditionary Forces hoped that the Germans could be forced to use the slower and more vulnerable sea route to the south.
Opportunities for operational group undertakings from the UK to disrupt German railway communications fell within the purview of Lieutenant Colonel Hans H. Skabo, the section chief of the Norwegian Special Operations (NORSO). Major William E. Colby, a 'Jedburgh' veteran, was appointed to command the Norwegian Operational Group.
Colby divided his group into two units. The main unit of three officers and about 30 enlisted men would be under Colby’s direct command and was identified as 'Norso I', and the second unit of one officer and 18 enlisted men would by commanded by 1st Lieutenant Roger W. Hall and was identified as 'Norso II'. The latter was to be the reserve or reinforcement unit for 'Norso I' or be available for a separate mission.
The Nordland railway had been the previous object of study to find the best targets in the region of Steinkjer to Grong, and arrangements were made for the local resistance organisation to provide a reception party of Norwegian personnel, despatched from Stockholm in neutral Sweden, to receive the advance party of the 'Norso I' team when was parachuted into Norway. It was planned that this advance party would jump into the area during the light moon period at the end of January, with the main body to follow during the next moon period, the main body onto a drop zone selected by the advance party.
The advance party of one officer and two enlisted men was briefed and prepared for the drop, but the arrival of a period of adverse weather then meant that the mission had to be postponed until the next moon period. On 2 March the advance party’s aeroplane took off, but found that heavy weather was completely obscuring the intended drop zone, and therefore returned to its airfield in Scotland.
Because of these delays and the German troop movements in the delay period, the selected target now had to be changed. Thus the primary objective became the demolition of the Grana bridge, while the secondary objective was any targets of opportunity which could be found for additional rail demolitions along that line. The advance party and the main body were then scheduled for deployment, just one day apart, during the next moon period.
On 24 March the mission was started by the despatch of eight Consolidated B-24 Liberator heavy bombers adapted as transport machines. A combination of navigational errors (one aeroplane dropped it men and their supplies in Sweden), mechanical problems on two of the aircraft, and difficult weather conditions over the drop zone then meant that only four of the aircraft made successful drops. Efforts to complete the drops were made unsuccessfully on 30 March and 6 April, and in total some 16 sorties were made and only 16 Americans and one Norwegian of the 34 men originally assigned to 'Rype' were actually deployed. Some 10 other men were killed in the crashes of two aircraft, and eight men were brought back to Scotland for later deployment.
Knowing that that earliest time in which his group could be reinforced was the next light moon period, Colby decided that the men he had under command were insufficient in number for a successful attempt on the Grana bridge, as had been planned, and therefore decided to concentrate his group’s efforts on cutting railway lines and destroying other bridges in the area from Jorstead in the north to Valoy in the south.
The first tasks of the 16-man group were the creation of a base of operations and the establishment of links with local Norwegian contacts. A Norwegian military officer, one of the members of the reception party, expressed a desire to remain with the group and to use his ability and credentials to handle future shipments through the Swedish system across the border, and it was this channel which was used later after the OSS headquarters in the UK abandoned further airborne efforts. A Norwegian officer who had joined the group in Scotland and parachuted with them into Norway soon found local friends who were ready to join the ranks of the unit, and these men provided invaluable throughout the operation. The owner of the farm at Gjevsjøen, which became the group’s first operational base, evacuated his family to Sweden to facilitate the OSS group’s use of his farm, and he himself joined the group.
On 9 April the group, now including five Norwegians (one of them a local with excellent knowledge of the area’s geography), departed to the selected rail targets some 15.5 miles (25 km) away. The crossing of the local mountains on foot and ski, when the snow was wet and sticky and the winter was strong, meant that the group needed four days to reach its first objective. It had already been established that most of the area’s tunnels and bridges possessed guard units, but reconnaissance found that the Tangen bridge was guarded only by frequent patrols, and this fact made it the sensible first target for attack. At about 06.30 on 15 April the group blew the bridge and withdrew without encountering any resistance, though it was later learned that three separate patrols were in search of them.
Now swollen to 25 men by the arrival of more men from the UK via Sweden, the unit left its base on 23 April to strike at the railway in the area of Lurudal. Divided into eight teams, the unit executed a co-ordinated demolition plan which destroyed 1.5 miles (2.5 km) of track and inflicted considerable delays on the German movement of troops.
The snow conditions were now becoming unfavourable for the execution of more longer-range operations, so it was decided that the group remain in concealment, especially as it was now known that the Germans were undertaking a major search effort. Even so, on May a five-man German patrol came into the farm and held staff Sergeant Marinus D. Myrland at gun point. As the possibility of a US surrender was being discussed, a nervous German fired one shot and a firefight erupted: all the Germans were killed and one of the group’s Norwegian auxiliaries was wounded. After being treated by the group’s medical attendant, this Norwegian was readied for delivery to Sweden by sled for further care.
When word came through of the German surrender, the group was ordered to stand by for the receipt of further orders. On 11 May the group was instructed to move to Steinkjer, the first of a number of stops where the group became involved in welcoming ceremonies and celebrations on its way to Trondheim.
Under the temporarily command of a senior officer despatched from the UK, the group was ordered on 18 May to travel to Namsos, where it was to to be used in the processing of some 10,000 Germans currently being disarmed. On 29 May the group moved by coastal steamer to Værnes near Trondheim, where it linked with the men of Hall’s 'Norso II' group, which had been divided from the 'Norso I' group in the UK as their was insufficient airlift capability. The 'Norso II' group had earlier been landed by air to perform a policing and protective role to assist in the German surrender at the airfield.
On 9 June the whole group provided a guard of honour for Crown Prince Olaf upon his arrival at Værnes, and then took part in the parade in his honour in Trondheim on 10 June.
On 14 June the combined groups were ordered to return to the UK, and was then readied for transport back to the USA.