Original: Despite the clever design, the roadway through the arch in the Bargate still had to be lowered and some secretive fine-tuning of the profile of the arch masonry was also required at the last minute.
Simplified: However, the roadway through the arch in the Bargate still had to be lowered to allow the trams to pass through the arch. Some secret changing of the profile of the arch's masonry was also needed at the last minute.