7720 - Diesel Freight Train Set

1980-1984
425 pieces, 3 minifigs

instructions
booklet, 24 pages
14.6 x 21.0 cm (A5)

4.5V Starter Set
from 6 years

In 1980, the LEGO Train line was refreshed and re-launched into what has become known as the grey era. As before, there were several entry points into the range, from unpowered push-along sets to the full remote control offered by the mains-powered 12 Volt system. Sitting between the two was the battery operated '4.5 Volt' system, of which 7720 was the sole representative in the first wave of new sets.

A-Model

Of all train sets from the first wave of the grey era, 7720 re-uses the most ideas and parts from the previous blue era. The red diesel locomotive looks somewhat blocky, the design is quite similar to that of set 183 from 1976. The most important improvement here is the fact that the locomotive can actually hold a minifig, which was introduced in 1978. Similar to set 7710, the heavy 4.5V motor is connected to the train base by only 4 studs. Once again this issue was improved in the successor set, 7722.

The first wagon is a blue battery car, which has faked, stickered doors and therefore very limited playability. It was carried over from the 1970s without any change, which means that it even has the red and blue connecting magnets so typical of the blue era. The second is a flatbed wagon, which is intended to carry the little bucket loader which is also included in the set. The last wagon is a freight car with brakeman's cab, it has an unusual long wheelbase of 18 studs compared to the standard short wagons which are 16 studs.

The track is a complete circle with an additional total of four straight sections. The set comes with a small platform with ramp, to load and unload the wagons, and a small yellow bucket loader, which is similar to set 6630 from 1981. Finally, this set features a small level crossing with two hand-driven barriers, a stop signal and two direction switches that help to operate the train, all carried over from the blue era.

This set was available until 1985, when it was succeeded by set 7722.

B-Model

The booklet contains instructions for 2 alternative locomotives, the first one a steam engine reminiscent of the blue era, the second one a charming tram-like vehicle.

based with kind permission on a series of reviews by Christian Andersch; revisions, editing and additional research by Fouke Boss.