1904 Franklin St, San Francisco, CA
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.
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
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
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,
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.