Powerlock: The Untold Story
30th Anniversary
We revealed the history behind the creation of Powerlock connectors and the development of the product through to its most refined version, the Ten 47 Powerline QC series. What has never been made public, however, are the serious issues faced during the initial tooling and development. On the 30th anniversary of its launch in 2025, it’s time to tell the story.
As previously explained, there were four people on the team: Tom McKechnie, who was in charge of the Veam business in Scotland; John Cameron, who was in external sales and had driven the development of Powerlock away from the Veam US L-series connectors; Walter Chalmers, the design engineer and the only one with real experience in designing a new connector series, having worked at Ferranti; and myself, Keith Gordon, as Business Manager, responsible for the commercial aspects and supply chain.
The Powerlock connectors were very different from the ones Walter had previously designed, being large, high-power, single-pole connectors. The base design was copied from the US L-series with some modifications. The L-series only included panel source and line drain, so we had to create the panel drain and line source. A secondary locking pin was added to the line drain to prevent accidental uncoupling, which was patented with John & Walter listed as inventors. The contact size and mating remained the same, but the mating system was designed by Multi-Contact to give a low-insertion-force, long-life contact.
Tooling Challenges and Design Compromises
When tooling the connectors for injection moulding rather than machining, some changes were requested by the toolmakers and moulders. They wanted a slight taper in the source connectors to ease removal from the tool—meaning the internal diameter wouldn’t be uniform. It would be narrower at the back and wider at the front. This required the drain connectors to have the same shape in reverse—narrower at the front and wider at the back to ensure a proper seal.
The connectors were keyed, but the toolmaker’s proposed method meant that keeping a key at the top of the panel drain would only allow a small angle difference between the connectors.
The moulding company offered to mould the hole in the line drain to accommodate the dowel pin that secures the contact in place.
The Testing Oversight That Nearly Ruined Everything
Once the design was completed, we placed orders for the tooling and components. A major complication was that there were four different connector types and five different keying options for each, resulting in a total of 20 different connectors. This meant a long lead time, and people were getting impatient.
Eventually, the tools arrived, and they began producing test pieces. Initially, they tested just one key from each of the four types to check sealing and voltage rating performance, and everything seemed fine. The moulder was then supposed to run all types to confirm the keying was correct. Walter and John were overseeing the checks. I understood that everything had been verified, so we started production of the mouldings.
Then came the fateful day when John told me that the connectors could cross-mate when upside down—meaning, for example, that a neutral could be connected to a phase connector. Shocked, I said, “But we ran all these tests and already made all the checks, that’s what we agreed.”
John replied, “No, we only ran them in all the colours to get pictures for the catalogue.”
I was stunned. I went in to see Walter—his face and entire neck were scarlet as he frantically worked on his CAD software. I picked up some pieces, and sure enough, they cross-mated. We had already produced thousands of mouldings, and the tooling we had spent tens of thousands of pounds on was suddenly useless.
A Second Major Issue: Cracking Connectors
Unlike working with metal, plastic flexes, requiring larger tolerances. Walter lacked experience with this and had been too willing to compromise to accommodate the toolmaker and moulder. He was simply too nice a guy.
I called Tom, who was offsite, and he immediately came in to discuss the disaster. What were we going to do?
The decision to tool Powerlock in Scotland had already been controversial and politically sensitive. If we didn’t find a solution, it was doubtful any of us would keep our jobs.
To make matters worse, we had already sent sample pieces out for customer trials so they could prepare their marketing material. Their feedback? The line drains were cracking. A simple tap on the connector caused it to split—a faulty tool design.
The Veam Group set up a meeting in Italy to discuss the direction of the power connector range as Italy, the US, and the UK all had three different designs. We weren’t exactly flavour of the month, and they hadn’t even been told about the keying and cracking issues yet.
The Breakthrough Idea That Saved the Project
For days, we tried to solve the keying issue using our existing tools, but we got nowhere. It consumed all our thoughts, even at home.
Then one evening, I had an idea: abandon the top key on the panel drain. This would allow us to keep three of the line connectors and only modify earth and neutral. We could achieve a 15-degree spacing and still use our existing tools for the drain connectors.
I jumped in the car and drove to John’s house to explain.
He said, “What about the source connectors?”
I’d missed that.
“We’ll just have to buy new inserts for earth and neutral,” I replied.
The next day, we presented the idea to Walter and Tom. They agreed this was the best solution. Walter flew down to the toolmaker to discuss the new designs but came back despondent.
“It’s impossible to mould them with the keys at those angles—it interferes with the water channel,” he said.
John & I were flying to Italy that afternoon. Before we left, I said to Tom, “I just don’t believe this is impossible. Talk to the moulder, see what he says.”
A £30 Fix That Changed Everything
In Italy, we handed over a pair of incorrectly keyed Line 1 connectors that could be mated upside down if forced.
Veam US head Al Bernardini was furious—he had originally driven the development of these connectors, and we’d taken his idea and turned it into something sellable.
We held our breath as he spun the connectors around… and mated them correctly.
“Good job,” he said.
The meeting went well, but we still had no solution for the earth & neutral inserts.
Back home, I asked Tom how he had gotten on with the moulder.
“Fine, I just took your approach—that we have to be able to do this.”
“And what did he say?”
“Oh, that’s no problem. We just need to add a new plate so the water channel enters from another position.”
The cost of the fix? £30.
What Can Be Learned From This?
It’s easy to blame Walter, but he was doing his best to satisfy everyone without real support. Design is about compromise—knowing what’s essential and what’s just a ‘nice to have.’
Challenge assumptions. Test thoroughly. Work methodically. And never assume something is impossible just because someone says so.
Today, Powerlock-style connectors are the market standard worldwide, offering improved safety and usability over their predecessors.
As the last surviving member of that team, I can say with confidence: every one of us played a role in making that happen.
Ten 47’s Powerline QC series is the latest evolution of the original design from all those years ago. Further details can be found here.
– Keith Gordon, Managing Director