to supplement the aging stock, the gb class 3 singe tram and trailer, from hønefoss karrosserifabrikk (høka) was ordered in 1954. delivered in september 1955, it was put into service in december. because of the increased traffic, a new signaling system was introduced in 1957, and a double track was built from bergsli gate to ila. this section had been causing problems for cars, since the trams would operate on the wrong side of the road. to allow a future 10-minute headway, a new signaling system was installed in 1958 up to ugla. up until then, tokens had been used to regulate traffic.