It is not known whether William Christensen and Hans Peter Nielsen were among the first batch of stranded passengers who were returned to Australia per the Beltana, which left London on 13 August 1914. However, both men were listed in the Electoral Roll for Waratah in 1916. So they must’ve returned home safely, eventually.
Little is known of Hans Peter Nielsen other than he was a Danish seaman who later became a carpenter and built the Waratah Methodist Church. He was also engaged in osmiridium mining at Savage River and Adamsfield. He died in Hobart in 1934.
William Christensen, whose real name was Hans Christian Wilhelm Christensen, was also a Danish seaman. At the age of 16, he went to sea as a sailmaker, visiting many parts of the world. In 1896, he settled in Melbourne and went into partnership in a ship chandling business. He later moved to Tasmania and was employed on the construction of the Emu Bay Railway (EBR) line as a scaffold rigger and splicer. He subsequently worked as porter, guard and engine driver for the EBR before working at the Mount Bischoff mine as an engine driver. He held first, second and third steam tickets as an electrical engineer in power stations at Mount Bischoff and Mount Magnet. He was survived by his wife and three children when he passed away in 1951.
According to his naturalisation record, William came from a small parish in the southernmost part of Denmark, which made it somewhat easier to trace his ancestry. This is also aided by the use of multiple christian names, which became commonplace in the latter part of the 1800s. However, if I were to search Hans Peter Nielsen, it would have been next to impossible to trace without his date of birth and birthplace. This is akin to tracing John Smith from anywhere in England.
So finding William’s naturalisation record was a bonus as naturalisation records are often more accurate than marriage records, obituaries and such.
Below is William’s ancestry chart and data sheet for anyone who is interested.
 Completed in February 1912, the church was situated at the north end of Main Street. The church was moved to Upper Burnie in 1950.
 The Advocate, 9 August 1951, page 4