JIS F 2007-1976 mooring Pipe is one of the bulwarks mounted marine mooring chocks, which is used to guide or lead the mooring ropes. The JIS F 2007 mooring pipe is also known as the JIS F 2007 closed chock, installed on the bulwark of the ships. The material of the mooring pipe is cast steel according to JIS G 5101 which is usually in ZG230-450 in China. Its inside shape of the mooring pipe makes the surface more smooth and can reduce the friction of the mooring ropes. And there are many stiffeners on the chocks to make the mooring chocks or closed chocks have higher SWL and much more stable on the bulwark during installation. It has two types according to its shape, which includes an oval-shaped mooring pipe and a circular shape one. The nominal size of the mooring pipe ranges from 150mm~500mm.
https://www.ysmarines.com/products/detail/mooring-pipe-jis-f-2007-1976-standard.html