sentences:  A relatively thin copper tube was reinforced by heavy cords and finally clad in leather (alternatively clad in leather straps first and then rope cords).While the weapon was light enough to be mobile (it required only a two-man crew to pull into position and operate ), and at the same time was cheaper in construction, the basic design proved to be flawed.The reinforcing materials acted as an insulator, and did not allow heat to dissipate fast enough.