In the past (pre 19th century), most heavy haulage and lifting needs were met by bulky chains or big ropes made of fiber. In the early 1830’s, a mine in Germany dropped a mine conveyance full of ore to the bottom of their mine and it was found that the heavy chains they were using to haul the conveyance to the surface suffered from work hardening and became severely brittle, leading to its failure.

As time progressed, other nations and people began to experiment with the fabrication of wire rope and, initially, each of them were essentially drawing hot steel through some dyes to create wires which were then laid helically together to form the wire rope. The type of steel that was readily available at the time was the same steel used to create ploughs for agriculture; thus the “Plough Steel” designation was used to denote what grade of steel was used to fabricate the rope.

Improvements were made to the ingredients of Plough Steel that allowed for a higher tensile strength of the wire rope. This new grade was aptly named, “Improved Plough Steel” or I.P.S. for short. Improved plough steel became the de facto steel to be used until it was once again improved upon, to the point where it is actually difficult to find Plough Steel grade wire rope in inventory at a sling shop.

Speaking of improvements made to the already Improved Plough Steel, once the recipe was perfected and it was found that wire rope could be made to have some extra strength. What did the powers that be name this new and improved wire rope…You guessed it, “Extra Improved Plough Steel.” EIPS offers approximately 10-15% increases in tensile strength over the old IPS depending on diameter. The higher tensile strength improves the minimum breaking strength of the wire rope. This, of course, will change the breaking strengths of the rigging mines and other industrial uses. This makes it important to know what type of wire rope your rigging is constructed from. If for example, a worker is referencing a sling chart for minimum breaking strength of a sling they should:

• a) check to see if the chart is referencing IPS  or EIPS 
• b) know if his sling is IPS or EIPS.
• Referencing an EIPS chart while lifting with a IPS sling could result in the sling being overloaded and breaking.

Currently, most rigging shops have transitioned to EIPS or are in the process of doing so. EIPS wire rope should be the standard in a modern day rigging shop and used for rigging such as wire rope slings, winch lines, and wire rope assemblies.

                                                                                  EIPS Sling Chart

In 1962 there was a breakthrough invention of a revolutionary product that we have all come to know as Wirelock® cold socketing compound. Why was it revolutionary? If a product came along that made it easier and faster to put a stronger termination on a wire rope, it could be argued that a lot of the mining sector would stand to benefit from such a product. 

Wire rope in and of itself is not very useful. To get any work out of a wire rope, something must attach to each end of it to enable it to pull. This is how most raw materials are brought out of underground mines. Usually one end of the wire rope is fastened to a winding drum and large, bulky thimbles or cappells must be installed on the opposite end to provide an attachment point. Although, where space was limited, some wire ropes would have to be terminated with sockets.

How sockets were installed (up until 1962 that is), required sliding the socket onto the rope, prepping the rope end, and pulling it down into the socket. The next step was to melt zinc babbit by heating it up to around 427°C to pour it into the socket. The socket itself would also have to be preheated so that the molten zinc would not stick to the socket wall.

Along came Wirelock®, which is touted as the world’s first “cold-socketing media,” which is much cooler than molten zinc, as it only ever reaches temperatures as high as 100°C after mixing. All of the other steps remain the same, but instead of starting the forge, you just get a stir stick, mix some sand into a pail of resin for 2 minutes, and pour it into the room temperature socket and wait for it to set. 

Wirelock all but eliminates the possibility of burns and other injuries from resulting from extreme heat of the Zinc process and the only real downside is that mechanical failures and downtime are quite prevalent when Wirelock® ends up in the hands of the untrained. Reading the manual supplied with the Wirelock® and hoping for a good socket is like reading the owner’s manual of your car and expecting to be a good driver. 

The best way to minimize socket failures when using the Wirelock® socketing media is to ensure that employees have participated in a formal, hands-on training course that reviews the core fundamental principles that everyone should know before they pour a socket that lives depend on.

The Northern Strands Wirelock® Socketing course reviews the fundamentals from the application manual and includes valuable lessons that we have learned through using this product extensively as a company over the last 50 years. We then walk the students through the process of pouring a socket step-by-step using a 16mm wire rope and corresponding socket.  Once the sockets are complete, they set for the requisite amount of time and then are destructively pull tested to ensure all the steps were followed correctly.

Put simply, Wirelock® has the potential to be one of (if not the) best ways to terminate wire rope. The benefit of using it can be found across many different industries, but just like any other tool in the toolbox, it needs to be used correctly to fully realize these benefits. An incorrectly poured socket that fails can lead to expensive downtime, injuries and even death should a socket fail.