Back in the day, a lighthouse was needed to show ships the way on their journey through Vestfjorden into the inner areas, and to lead the marine traffic towards Tjeldsund, Ofoten, and Tysfjord. The lighthouse director decided that Stangholmen would be an appropriate place for a lighthouse.
A lighthouse with a fixed light was chosen. The allocation for the construction of the lighthouse was placed in the budget for the period 1863-66, and it was estimated to cost 6274 Norwegian Speciedaler.
The owner of Stangholmen was willing to sell it, but because he could not provide an unencumbered deed, it was decided that the Lighthouse Authority would pay a yearly rent of 3 Norwegian Speciedaler instead. In addition to that, the employees of the Lighthouse Authority gained the right to collect water at Tranøy. A log building was constructed, as well as a shed with a stable and space to store wood and oil, and a boathouse with a rail to pull the boats out of the sea. A fourth-order lighthouse lens with a fixed light was mounted. The lighthouse was lit on the 19th of September 1864.
During a storm in the winter of 1867, part of the protection wall by the lighthouse was destroyed by the strong waves. In 1877 there was another storm, where the sea covered all of Stangholmen and severely damaged the protection wall. The houses and the cistern were all filled with seawater.
In 1903-04 there was a suggestion to replace the fixed light at Tranøy with a revolving light. The budget allocation for this didn’t come until 1909-10. In 1910, a new light was mounted and the lighthouse now blinked two times every six seconds. In 1906, the lighthouse got a water tank in the basement, and in 1908 a quay with a crane.
In 1933, a list of lighthouses that should have a fog signal was created in cooperation with the sailors’ associations, and Tranøy was on the list. 120 000 Norwegian Kroner were allocated to buy a diaphone. The 20-meter-tall iron tower at Moholmen outside of Kabelvåg was disassembled and moved to Tranøy, where it was mounted (at a total height of 28 meters). The lighthouse light from 1910 was kept, as well as the installation from Moholmen. On the ground floor, a machinery room was built. Three compressed air tanks were placed on the floors above, while the diaphone was mounted on the top floor. The new lighthouse was put into operation on the 1st of November 1936. This meant more staff members were needed – four men instead of just one. For that reason, three new buildings were constructed in addition to the tower. A house with two living units, a shed, and a boathouse. There was now a lighthouse keeper, a first assistant, a second assistant, and a backup person. They only had work when the light was on between the 7th of August and the 30th of April. In 1959 the lighthouse was electrified, with a diesel generator as a backup.
A new light with a second-order fixed lens (middle part) and a 1000 W lamp was mounted. An electric compressor was installed for the fog signal. Originally, a rowing boat was used to cross the strait from Stangholmen to the mainland, but this could at times be a lot of work. In 1969, a 250-meter-long footbridge was constructed across the narrow strait. A few years later, Tranøy lighthouse became a lighthouse manned by alternating shifts, so the families left. In 1983 the fog signal was removed, and the staff was reduced from four to two people. In 1986, the lighthouse was automated, and five years later, on the 5th of June 1991, the last lighthouse keeper’s shift ended. On the 1st of July 1993, Tranøy lighthouse’s adventure as a tourist destination started, and the first owners were Stig Lexberg and his family.