Home > 291 Geary St.
684 Ellis Street
The Chew Bldg.
Cartwright Hotel
1904 Franklin St.
291 Geary St.
Mills Building

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291 Geary St.

1904 Franklin St, San Francisco, CA
Contractor:  Schindler Elevator Co., Inc.
Alteration of an Otis duplex to add rear openings to car #1, requiring relocating the counterweight to the side, a new rail stack, modifying the platform and cab. 

RCB Elevator Consulting, LLC performed the elevator engineering required to make the conversion and collaborated with the owner's structural engineer.  This included performing all field surveys.

Project Description 

This project was somewhat unique in that two older separate adjoining buildings were combined into one.  However, the floor elevations did not match between the two structures.  Openings were cut in the adjoining walls to to connect the common areas and hallways.  Short flights of stairs were added to connect the offsets in elevations.  But in order to obtain full ADA accessibility requirements, an elevator had to land and open at the different elevations of each building.  The rear wall of a bank of two elevators aligned with these adjoining buildings' exterior walls.

Therefore, it was decided to provide elevator access to the adjoining building by adding rear openings to car #1 of the duplex.  This required relocating the rear counterweight and its rails to the side wall.  Extensive building demolition and re-construction was required to extend a portion of the elevator hoistway side wall at the back of the car main guiderail to house the counterweight. 

The two elevators in this project had been fairly recently modernized with new Hollister Whitney machines, sheaves, governors, safeties and counterweights, new MCE controls, cab upgrades and fixtures.  It was the owner's wish to retain as much of this new equipment as possible.

RCB Elevator Consulting, LLC worked out the design of the new counterweight guiderail stack, including special bracketing and connections, to obtain the same dimension between guiderails (DBG) as the original elevator.  Therefore, we were able to reuse intact the fairly new Hollister Whitney counterweight frame and filler weights.  We were also able to reuse the overhead sheaves by relocating them onto new, longer overhead sheave beams. 

The pictures below show the demolition work underway with the elevator equipment in its original locations.  Feel free to open and view our elevator shop drawings by clicking on the drawing image below the pictures.  The drawings show the work to be performed to affect the conversion.


The recently installed Hollister Whitney counterweight was reused, relocated from the rear wall to the side wall to make way for the new rear entrances. 

These two pictures shows the demolition and temporary barriers for the new hoistway counterweight pocket to the back of the L.H. car guiderail.

The upper sheaves and beams were rotated to change the outer rope drop to the new, side counterweight location.  New, longer beams were used to support the original, relocated sheaves.

These lower sheaves and beams for the rope drops from the machine to the car remained in place unchanged.

Drawings & Engineering

Click on the drawing above to open the full drawing set in PDF format.  To see drawings in landscape view, click on your Adobe Reader's Rotate Counterclockwise image button.  Note drawings cannot be printed or altered.  All drawings and artwork are the property of RCB Elevator Consulting, LLC and may not be used, copied, or in anyway used without the owner's consent.


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