29A lock by Jim Engle

Published: 10/25/2021

I decided to write down what I know about the 29A lock because the story of how I found out what I found out is so intriguing. I was at one time about 21 years ago a employee of the Cincinnati Bell Telephone Company. During my 23 year career I spent the majority of my time in the public telephone group. CBT was a very small bell company and as a result in the coin group you were exposed to every aspect of the payphone group. Since we were also not a wholly owned bell company by AT&T we did not have to dissolve our relationship with them as the other bell companies did. As a result of this I was exposed to everything that AT&T cranked out on the public telephone side as well as the standard running of the bell coin department. As a result of understanding the of how things worked between the bell companies it has placed me in a unique position of investigating and understanding why or how something was done at the telephone company. In the process of collecting payphones I began to look closer at the 29A lock. I knew that each bell telephone company had their own 29A locks. I did not know how or why it was that way. I just knew that in CBTs case their lock was 29A 43.

One day I was on eBay and saw a really nice chrome western Electric payphone for sale. The seller stated it was the last payphone that was sold to the bell companies by AT&T, so being a collector I bought it new in the box. I just happened to talk to the seller because he was not far away and I was just going to send someone to go pic up the phone from him. In the process of talking to him he stated that he was formally with AT&T had worked in there public telephone group. I explained my history and the conversation ended with him saying (I have a 3 slot prototype vault door would you like it?) I said yes. Well I received the vault door and that is where my adventure starts.

But that is not the interesting part, where was the # 1 lock used, what bell company used # 1? Well I thought it most be the oldest bell company or perhaps the first? So I called the guy back that sent it to me and started asking questions, of course as every other ex- bell telephone guy I come across, especially the guys that were in the labs it takes time to give you what they perceive as classified, top secret information. Never mind that the Bell System is long gone, they are still afraid that the phone police are going to come and steal their pension. so after two more phone calls over 6 months I finally found out that the 29A number one lock was only used by Bell Labs. It was their lock used on all the stuff they produced as prototypes. It was never used outside of bell labs.

So now of course I have the lock but I need the key. I call him up again and I ask do you have the key, he tells me yes but he wants to keep it, he also states that he has a document that has all the 29A locks by number, where they were used and all the key codes to cut any 29A lock that any bell company ever used. Now I have hit the mother lode. Up to this point you had to have the lock to cut the key, so if you were lucky enough to find all the 29A locks you have to destroy the lock to make the key, and some locks are impossible to find like the #1 lock. Now I need to get the codes and then I need someone with a bigger brain then me to cut the keys. Someone skilled in doing reverse engineering of tough to find items. But first I need the document. So I call the fellow up again and I start offering to buy the top secret document that will cause the phone police to strip you of your stripes and pension. Problem is, there are no phone police and nobody cares about the document anymore. You cant even find anybody at the phone company who knows what a 29A lock even was. For to years I called the fellow off and on and kept raising the price for the information. Finally after 3 years of phone calls he finally agreed to meet me at a top secret location along the expressway. Which was Bob Evans. I sat down at the table and offered to by him lunch but he told me he was to nervous to eat. He had a guy with him who was also bell labs which had all kinds of interesting info to talk about bell system locks. I paid the guy for the info and I can't believe the piece of history I now had. Something that was about to be lost forever like so much of the other stuff we try to find as phone collectors.

Note up in the corner the date is 1975. The document is 41 years old. The list can be viewed and printed at the TCI archives. This is a picture of it. The next task I had was to make the keys. The keys to every known 29A lock on the page. That task was beyond my ability so I involved a fellow collector who was very skilled at reverse engineering just about anything. He figured out the key codes(which I have never released except to him, they are still not in the public domain) which were made to match up to a special machine we did not have. After he cut the keys in brass he decided that they were not strong enough so he spent months creating blanks at great expense made of the closest thing he could find to the original nickel-steel. There are now a few sets of the keys made out of very hard steel. The history has been preserved.

The process for making the steel blanks are cost prohibitive, it cost thousands to produce 3 sets. However I can check and see if the fellow is willing to make brass sets of the keys, they work, they just do not last as long. They are fine for the hobby part of this. As with all payphones the locks and doors will eventually be the most difficult thing to get. 3 slot upper and lower locks are getting harder to find all the time. 10 L locks used to be common as dirt and now are very hard to find. Upper locks 10G,21B,and 29S are going away fast. The 29A lock will go away also over time and since they all take a different key based on area some locks are already gone. I also collect the locks, I am trying to get everything on the list I posted. It is tough. Early bottom locks like the 15A,15B, 14A are already almost impossible. I also collect the original keys 29A. They are harder then the locks because only a few ever existed, at CBT we never had more then maybe 50 keys at a time and there were 12,000 locks. I ended up with all their keys it was another 5 year process. The original 29A keys do not tell you on the key what lock they fit. They only have letters and numbers on the shaft that was the code used to assign the key to a installer. So if you see them for sale you have no idea what they fit unless you have the locks to put them in to try.

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