A cable layer is a deep-sea vessel used to lay underwater cables on ocean floors for telecommunications and electric power transmission. Cables are stowed on the vessels in a spiral cable carousel and unreeled according to the speed at which the cable laying takes place. Braking needs to occur regularly while the cable is lowered onto the sea floor to control the laying speed. This frequent braking, along with atmospheric problems such as salt, water ingress and extreme temperatures creates a pretty tough working environment. To safely dissipate the excess energy created by braking, a bank of braking resistors is required. These resistors, like NUAL series, FLR200  must be able to withstand harsh, corrosive environments so that the components do not degrade over time.

An additional challenge that these braking resistors face is insulation resistance. As the DC braking voltage of the unit cannot be connected to the vessel, it is not possible to use any of the re-generative capacities of a motor to power the ship. This means that a large resistor is required to dissipate all of the braking energy, as none of it can be fed back into the system.


To combat these challenges and manage excess braking energy onboard cable layers, engineers need to turn to a rugged solution. Most ships have a chilled water system, making it straightforward to incorporate resistors into the cable laying infrastructure.

However, if the end users chooses to cool the resistor using sea water, they would require a different solution. In this case, titanium-sheathed elements in high grade stainless-steel vessels are preferred as they are able to withstand constant harsh environments. This means that the resistor’s voltage capabilities and its durable materials can safely dissipate all of the excess heat created during cable laying braking to make sure the operation is carried out without causing harm to other components on the ship.


Underwater cables are the invisible force driving the internet. These cables are a critical part of modern infrastructure and making sure they reach the ocean floor without any problems is an important task. To successfully manage the frequent braking that is required during this process, a durable and capable resistor should always be found onboard. Microhm Electronics provides various options for customer's options.