Between the wars
After the Armistice of 11 November 1918, Rotterdam was dry docked in Glasgow, as the Netherlands had no dry dock big enough for her.[26] On 24 January she left Rotterdam for Hoboken carrying fewer than 100 passengers, but in Brest, France she embarked many US troops. She continued to repatriate US troops for some months, and on 24 January 1919 she resumed civilian service between Rotterdam and Hoboken. In 1920 she was converted from coal to oil fuel.[27]
At the beginning of April 1921, a delegation of the World Zionist Organization sailed from Rotterdam to Hoboken aboard Rotterdam. They included Albert Einstein, Ben-Zion Mossinson, Menachem Ussishkin and Chaim Weizmann. Also in April 1921, Rotterdam became the first ship to use the new 46,000-ton dry dock at Wilton's Dok- en Werf Maatschappij in Schiedam.
In the 1920s Rotterdam resumed winter cruises from Hoboken to the Mediterranean, including in 1923, February 1924,[28] and February 1925.[29] In 1929 she was refitted as a two-class ship, with berths for 517 first class and 1,130 tourist class passengers.[4]
The Great Depression that began in 1929 brought a global slump in commercial shipping. On 24 December 1930, NASM revised its fares for 1931. Fares were seasonal, and until 1930 the company had divided them into summer, winter, and intermediate. For 1931, NASM abolished the intermediate seasons, simplified the fares to summer and winter only, and announced significant reductions. On Rotterdam, the minimum first class fare would be US$200 eastbound from August to April, and the same westbound from November to July. The minimum first class fare for summer, which now included the former "intermediate" seasons, would be $220.[30]
Rotterdam was a coal-burner. At the beginning of September 1932, members of the Bond voor Minder Marine Personeel (BMMP) trade union working for most Dutch shipping lines struck for better wages. As Rotterdam left Boulogne on 4 September on a westbound crossing, her ships' stokers demanded that she terminate her voyage and return to Rotterdam.[31] Her Master anchored her near the West Hinder lightvessel, where a detachment of 30 Dutch Marines boarded the ship from a pilot boat. The ship returned to Rotterdam, where 11 members of her crew were arrested for mutiny.[32] On 7 September, NASM announced that it would not re-hire 400 BMMP members.[33] Rotterdam and other NASM ships remained in Rotterdam as the strike continued.[34]
On 15 September some shipping lines reached an agreement with the BMMP, oncluding reinstatement of the 400 members that NASM had dismissed, but BMMP members at Rotterdam voted to reject it.[35] However, the "contact commission" between the shipping companies and the BMMP established that an aggregate of the votes from the separate mass meetings at Amsterdam and Rotterdam produced a majority in favour of returning to work.[36] NASM crews resumed service. SS Veendam (1922) left Rotterdam on 17 September, and all ships returned to normal their schedule.[37]
Late in 1933, Rotterdam was reconditioned, and an artificial beach was installed in one of her well decks. She started her cruising season on 18 November, leaving Hoboken with 450 passengers on a cruise to the West Indies.[38] On 23 December she left Hoboken on a nine-day cruise to Nassau and Kingston.[39] On 3 March 1934, she left Hoboken on a cruise to Central America.[40]
By 1930 Rotterdam was equipped with wireless direction finding. By 1934 the new four-letter call sign PHEG had replaced her code letters and three-letter call sign. Also by 1934, her hull had been repainted white.[4]
Volendam and her sister Veendam were rarely in the same port at the same time. One exception was on 16 March 1935 in Hoboken, when Veendam arrived from Rotterdam in the morning, and Volendam was already in port, waiting to start a cruise to Nassau and Bermuda on 23 March. Rotterdam, Edam and the cargo steamship Beemsterdijk were also at Hoboken on the same day. It was rare for five NASM ships to be in the same port on the same day.[41]
On 29 September 1935, Rotterdam was cruising off Jamaica at the time of the 1935 Cuba hurricane when she ran aground on Morant Cays.[42] The Elders & Fyffes banana boat SS Ariguani took off all of her 460 passengers and 70 of her crew, and landed them at Kingston.[43] On 1 October, NASM's SS Volendam left Hoboken, without passengers.[44] On 7 October she left Kingston carrying 350 of Rotterdam's passengers and crew,[45] and on 11 October she landed them at Hoboken.[46] Rotterdam was refloated on 5 October.[47]
In January 1936 HAL reclassified Rotterdam, Volendam and SS Veendam (1922) as "cabin class" ships. Rotterdam's one-way fares were reduced from $169.50 to $161.50 in the summer season, and from $161.50 to $153.50 in the off-season. HAL was the last major shipping line to adopt cabin class.[48]
In 1937 Rotterdam made a summer cruise to the North Cape and the Baltic. In Leningrad the Soviet authorities refused to let some passengers ashore from Rotterdam and three other ships. The reason why they chose certain passengers for exclusion was not clear.[49]