Nevertheless , the UST - 26 had its own disadvantages .
Trials performed in March 1936 showed the UST - 26 was an improvement on the series - produced ST - 26 ( for example , the bridge raise operation did not require crew exit ) .
The improvement     had ST - 26 's own disadvantages .
Trials performed in March 1936 showed the UST - 26 was an improvement on the series - produced ST - 26 ( for example , the bridge raise operation did not require crew exit ) .