Picture of the month

This month, I present the mysteries of the second bridge series.
The first bridges that were assembled using screws were probably not as successful as expected. 
Completing a bridge takes minutes for even the most experienced adult.  The second series tried to alleviate this by introducing a bridge structure that could be set up in two movements from interlocking elements. Interestingly, this simplification process stopped at two forms. Neither larger nor more varied forms were envisaged for the construction of further bridges.

A bridge assembled using sliding elements is slightly lower than a bolted bridge, so a "leg" must be added to the shorter edge of the base to achieve the same height.

Another idea has also come up in the development of the metal elements. The trial became the last addition to the small caliber. The change came quite "on the fly". The last page of the building plan booklet for the 19 (17A) set shows a decoy construction using only stones. In supplementary set 19A, after the booklet was completed, a section of stones in the box was replaced by metal roofing elements. In principle, the roof is very simple to assemble. A crossbar can be slid onto brackets of different heights to make a structure resembling a gate. Two metal plates are placed on top of this. The innovation is very nicely represented in the plan booklet, but it is awkward to build. The support wobbles and is only really stable when the roof slab is placed on both sides.

To make matters a little more difficult, the roof would have to be covered from the right and left with two-dimensional walls. These walls are very tippy and not at all a pleasure to erect and then maneuver around with the building hands.

In the process of reforming the bridges, the development of the small-caliber line was abandoned, so the second series of bridges is only large-caliber. 
When the KK series was discontinued, based on the experience of the small caliber NF21 box, someone thought it is a good idea to incorporate these roofs into the second GK bridge series. This new bridge series complements the classic GK NF series by allowing the construction of lighter weight roofs and bridges. The two-direction development is not visible in any one structure at the same time. The new elements can be used either to build a bridge or to build a larger house with a metal roof. The two-way expansion results in either bridges or roofs remaining in the box after construction.

The bridge series was experimented with for eight years, and then new roof and bridge solutions were introduced in the year of Richter's death, 1910. This next solution did not bring a final victory for the builders either. The metal elements of the DS series were probably also made under Richter's personal supervision. This series will be presented next month.