On a trip to NYC I got to tour the WTC while Swift CEC was doing a mod..Machine rooms control either A Base or B Base, and if memory serves me correctly one of the early GF closed loop controls.. I actually got a print around here somewhere..It was very, very, cool...

Largest I maintaned was a 75 story, B Base, 140 selector, 1400 FPM...

Dave, thanks for posting the video. I've always been amazed that Otis was able to make their pie plate selectors work so well for so long. Like you said, that selector really is a Marvel in egineering.

Founding member of the "6850" Fan Club!

J/k!

and there are still a lot of 6850s around as well, owners to damn tight to upgrade....can really comprehend that but even some of the major sites are upgrading the later model 401s etc...

I get a kick out of watching the young guys getting their 1st look at a 6850 or any other mechanical selector..Pretty funny listening to them..

"Where do I plug my PDA"..

Much less the mysteries of the open loop...LOL...

I can,t imagine working on the 1400fpm selectors how far away from the floors did the sls start slowdowns sequence?

the video is very interesting. ive never seen that type of otis selector which is very different than the more open pie plate/finger contact style not the squareish type there in the video. that must of been the last version before 401's? it certainly looks more robust and accurate.

Uppo...

Those were called if memory is not fading 140AY selectors. You had wings held up by coils that would drop once you dropped HX on the SLSs and allowed the contacts on the leveling wings to take over the function of HX, HSL, TL, and direction..Had stopping lugs and Dogs like a 6850, but the wings were different rather than a leveling ring with contacts you had wings with roller actuacted contacts....

I was actually in this job about a year before the buildings fell. Swift CEC had sold a modernization at the building, and the building at that time was being maintained by ACE elevator, after the Big O, lost the contract to them. The mod was nearly completed when the attack occured. Machines were 339's (I believe) I've only seen one that size at that's at the Stratosphere in Vegas. I took care of several of the little brothers of this which had the 269 machine...(The 269's would run 1400 FPM, with a 6500. LB capacity cab. ) Yeah these were big machines.

From what I remember of the job it was originally B base Otis control. (TTL logic) in the dispatch. Nand's, And's Nor's and Or gates. If it had touch tubes they called it A base A little different than B base but not much.

And if I remeber correctly this job had a specialized circuit that acutall created a close loop on the generator field...

But you know...
Memeory's the 2nd thing to go...

I was actually luck enough on my visit to snag a set of the original Otis prints, that I have somewhere stashed in pile of junk I call an office. The ACE guy that was putting the Swift stuff in gave me a set saying they wouldn't be needing these anymore. Course it wound up they didn't need the Swift stuff either.

Interestingly enough, Big O had the job under contract during the 1st attack. Many brave souls, spent days on those 2 powerless jobs, floating passengers out of the elevators, working to restore some kind of service for emergency workers. (The bomb in the garage took out a good portion of the building buss)..

A few guys for the Big O actually recieved citations from the city and the state for heroism and bravery. I've hear stories of helicopter rides to the roof etc....

Of course in the final attack none of this was possible as the buildings were evacuated..

I'll dig around and find those prints..I remember it was a super cool installation, and I was fortunate enough to have seen the machine rooms but the hatch as well...

Made my blood boil when I watched them go down.. Still does..

One correction...TTL logic = Transistor, Transistor logic. All gates. No processore. Use a regular logic probe and logic diagram to troubleshoot. Logice diagram was Boolean logic named after Charles Boole the english mathemetician. Charles Boole actually created this wierd math that utilized a numbering system of just 2 numbers. (0 and 1). and all the laws and theorums for this system. It remained a mathematicl curiosity for a few centuries until the advent of the digital solid state cicuit which of couse only has. Off and On.

The B and A base actually used a different earlier version chip set instead of TTL which was DTL. (Diode Transistor Logic). Main difference is a specialized logic probe to read DTL logic (Still available). and the logic diagram was called Goolean..(I believe Goolean after an engineer Big O had that designed the logic) rather than Boolean logic which is what they taught at universities at the time. Same logic principles though.

Oh Yeah...One more thing...
The logic is almost the identical logic used in the VIP 260 relay dispatcher, but put into Boolean logic.

thanks broke. yes it certainly looks different than the normal 6850 otis selector with drop down levelling ring. i think in melbourne the highest building with this 260vip control is about 25 floors, when the higher buildings came on the new electronic gear was up and about (401's)with other companies also having their own designs. so was this type of selector the lastest type?
it certainly sounds like otis redesigned the action of the pall
magnet stopping. either way the engineering of them is astounding and its no wonder these lifts are now getting modded as the skillset of adjusting them is just about gone including at otis. i am lucky as i had an old adjuster to teach me the finer points. the company i did my training with eliminated selectors in the late 60's and used relay logic instead(which is great for putting in car/landing calls)