He was born on October 23rd, 1882 in Avaldsnes, Karmøy, Norway, the son of Johannes Sakariasen and Berta Johanna Andersdatter. He was the fourth of six children.
When he was 15 years old, he got a job in a shop in Haugesund owned by Matias Lillesund. Later he worked in Leversens bakery. There he met Mr Gaut Mathiesen who persuaded Bernt to go with him on the fishing boat Ingeborg Christina. He travelled to Iceland for work in 1902 and stayed there until 1904.
In 1905 Bernt was in the military forces in Norway. There were fears that war would break out between Norway and Sweden (Norway gained independence from Sweden that year). Bernt was prepared to fight against the Swedes if necessary, but the conflict was resolved without bloodshed.
Bernt then traveled to America, working on different boats but without great success and in 1910 he returned to Haugesund.
On January 28th, 1911 he was married to Ahna Karoline Hansdatter from Avaldsnes in Førdesfjorden church.
In 1912 Bernt sustained an industrial injury. He was advised by his physician to find lighter work in America and thus there was no alternative but to return to the USA. He found a job in New York. Bernt was originally due to travel to New York on the DFD Line's Hellig Olav, but a lack of space forced him too book passage on the Titanic, which he boarded at Southampton as a third class passenger (ticket number 65306, £8, 2s, 3d). Accompanying Bernt was a family friend, Lena Rasmussen. On the Titanic Bernt shared a cabin with fellow Daniel Danielsen Grønnestad, and Ingvald and Konrad Hagland who all came from the Haugesund area.
In interviews in Haugesund newspapers Bernt told what happened after the Titanic struck the iceberg:
Bernt was initially reported lost in an article in Haugesunds Avis April 25th, 1912. However, in New York, while resting at St Vincent's hospital, Bernt alerted his wife of his safety by letter. It is unclear whether Bernt received compensation for his loss of property in the disaster.
Bernt returned home after having stayed three months in New York. His wife Ahna Karoline would not let her husband work on boats any more. Bernt eventually got work as a stonemason.
Ahna gave birth to eight children: Any, Alfred, Sven, Kristian, Johanna, Bernhard, Tordis and Johannes between 1913 and 1929. The family also purchased a farm in Bratthammar, Førdesfjorden near Haugesund, and "Bratthammar" became an addition to the family name, and this is how Bernt is frequently listed on passenger lists.
In 1920 Bernt got a job as a postman in his home village. For that purpose he used a bicycle. He was faithful to his duties, even once there was a flood, and had to get help from two ladies to carry him on a string above the flooded area.
In 1952 Bernt was 70 years old, and he retired from his postal duties. When he retired the inhabitants in his home village had a big party for him due to their thankfulness to his long and faithful service.
From 1927 to 1962 he worked for the Førdesfjorden church to keep the church and the graveyard in good order. When the Haugesunds Avis came to interview Bernt on his 80th birthday in 1962 he was busy chopping wood as the journalist arrived. In the resulting article he was praised for his ability to recall the experiences of a long life.
Bernt Johannessen-Bratthammar was widowed in 1960, and he passed away on December 1st, 1962 at the age of 80.
In the obituary in Haugesunds Avis on December 3rd, 1962 Bernt was described as a very nice and faithful person, who had many friends and that he could tell in details of his experiences aboard the Titanic. In the death notice in Haugesunds Avis December 5th, 1962 it was announced that Bemt would be buried at Førdesfjorden church the next Friday. Family, friends and others who knew him were asked to come to the funeral.