Here's an interesting piece of hardware used on Indotelegraph. This is a insulator-mounted strain clamp. The hook on the right is one of the clamps. All the parts were made in cast-iron except for the wedge. This was used to create anchor points, loops of surplus wire for maintenance purpose, dead-end fuxtures on revision points etc.
This looks pretty complex for a telegraph line even by early standards but Siemens probably went for maximum sturdiness with this project.
This is probably the reason why they produced raplicas of old insulators for this line during it's later years. The 'collar' only fits the original insulator's head.