A former gymnast, Lammers joined the local track club in right after the war. His sprint talent was quickly noted, and he was picked to represent the Netherlands in 1946 at the European Championships in Oslo, placing fourth in the 4×100 m relay (with Jo Zwaan, Gabe Scholten, and the non-Olympian Chris van Osta). Two years later, he won his first Dutch title, in the 200 m. Lammers also contested in that event at the London Olympics, reaching the quarter-finals. In the final of the 4×100 m relay, the Dutch team, with Lammers, came sixth. Lammers' greatest international success came in 1950, when he gained a 200 m bronze in the European Championships, while claiming the sprint double at the Dutch Championships. Lammers had hoped to close out his career in Helsinki, but a torn muscle ended his hopes. Instead, Lammers got married that year and worked as a garage keeper until retirement.
Personal Bests: 100 – 10.6 (1948); 200 – 21.6 (1948); 110H – 15.6 (1948).