How does the Spear fishing tool grip onto lost pipe?

The spear fishing tool effectively grips onto a lost pipe by utilizing expanding slips that tightly engage with the inside wall of the pipe. This mechanism leverages the design of the slips, which can expand when activated, creating friction and a secure hold within the pipe. The expanding feature is crucial as it maximizes the contact area against the pipe wall, ensuring a stable grip that can withstand the forces involved when retrieving the lost pipe.

In contrast, other methods such as hydraulic mechanisms or suction do not provide the same secure mechanical connection to the pipe's internal surface. Hydraulic systems may be employed in different tools for various applications, but in this context, they do not specifically address gripping lost pipes. Magnetic attachments also are not suitable for pipe retrieval, as most pipes are not made of magnetic materials. Suction, while effective in specific scenarios, lacks the necessary grip for effectively retrieving items from the inside of a pipe. Thus, the mechanism of expanding slips is the most reliable and efficient method for securing a grip on lost pipes.