Building Maintanence Unit

Metropolis | New Project Update

news-rendering Metropolis is a multi-use high-rise complex of buildings located in downtown Los Angeles.

Sky Rider has been contracted to provide window washing equipment on the four main towers. The use of BMU’s (Building Maintenance Units) has become the new normal for window washing equipment on modern high-rise buildings and these buildings are no exception. Highlighted here is the most recent BMU installation on this complex. As can be seen on the attached drawings and photographs, the BMU performs multiple actions including traversing, vertical telescoping for storage, horizontal telescoping for varying outreach and platform rotation to access every window of the complex façade. The platform spans 38 feet of façade.

Martin Villegas (President) and Carl Gray (Founder) pose in front of the BMU. It is currently in use for construction activity. Note that the building in the background is the 73 story Wilshire Grand tower now in completion with a Sky Rider supplied BMU. Watch for future news on this installation.


Modern Updates to LA Twin Towers

City National Plaza City National Plaza

City National Plaza

In 1971 the original ARCO Center towers were built in downtown Los Angeles using a Manning & Lewis Wallglider roof car and platform system. 35 years later, with lack of availability of replacement components and the constant maintenance requirements, it was evident that the technology was in need of some modern updates.

Now referred to as City National Plaza, Sky Rider Equipment Co. was hired to install easy to maintain Building Maintenance Units (BMU’s) on the Paul Hasting and City Plaza Towers. Utilizing a gantry crane, the BMU's were hoisted to the rooftop of each tower, and later used to remove the old machines.

More information about the City National Plaza Building Maintenance Unit project can be found by clicking here.

Custom BMU Provides Solutions to LA Hotel

The New Otani Hotel The New Otani Hotel The New Otani Hotel The New Otani Hotel The New Otani Hotel The New Otani Hotel Originally built in 1975, The New Otani Hotel, in downtown Los Angeles was designed with no means of providing window washing. Thirty years later, Sky Rider was hired to provide a window washing system to the 255 foot tall, 21-story structure. Several major challenges were immediately apparent:

a) no means for raising equipment to the rooftop would be available

b) the parapet was 15 feet high

c) a helipad was present, somewhat higher than the parapet, creating a clearance problem in two locations

d) the 21st floor was cantilevered out in four locations. Most of the East elevation was cantilevered as were three additional corners

To access all but one of the cantilevered corners a Building Maintenance Unit (BMU) with platform was provided. The BMU was designed with an articulating “approach system” to bring the platform in under the building cantilever.

Click here to continue reading about the solutions Sky Rider found to the interesting challenges at The New Otani Hotel. A detailed PDF download of the project is also available on the project page.


Sky Rider Newsletter | June 2014 | Century Plaza Towers

Sky Rider is pleased to announce the completion of the Building Maintenance Unit (BMU) installation on the two Century Plaza Towers. As previously noted in our February 2014 Newsletter, the towers are 571 feet in height and were completed in 1975. These towers have been a famous part of the West Side sky line since their construction. In the 1980’s detective series, Remington Steele, the towers were depicted as their headquarters. Numerous commercials have been shot using the towers as a backdrop and, most recently, The Green Hornet featured scenes in which the towers appeared prominently.

Because of the triangular footprint of the building and the sloping cut at each corner, the original window washing machine could only access the glass portion of the curtain wall. When it was necessary clean the aluminum corners, outrigger beams and transportable platforms had to be utilized to accomplish the task.

Sky Rider worked with Gondolas in Design (GinD) to design BMU’s that are able to access the entire building, saving substantial window washing and metal cleaning cost. These BMU’s operate on a runway with motorized steering wheels. The BMU may be operated both from the rooftop and from the platform. The controls include platform elevation, platform rotation, raising and lowering of the jib, steering and right and left traverse. Elevation is controlled through a Frequency Inverter that allows ramping of the up and down functions for smooth, jerk-free operation.

The platform is suspended from four wire ropes that are wound on a multi-layer drum. The drum system provides several advantages over a traction hoist system. First, the drum is gentle on the wire ropes providing an extended operating life. Second, because the wire ropes are fixed at both ends, electrical conductors can be placed inside the wire ropes for continuous control communication between the BMU and Platform. This eliminates the need for Hanging control cable, radio frequency or electromagnetic control which is particularly prone to grounding and service interruption. And, finally, the platform will remain relatively level without operator intervention.

The following pictures depict the completed BMU on the rooftop. For more information on the buildings, the following links have been provided:

Century Plaza Towers BMU Figure 1. The completed BMU (One of Two) on the Century Plaza Towers. Note the counter-weighted Jib arms with a rotating spreader bar suspending the platform. The BMU is mounted on a base assembly with eight caster wheels to distribute its load on the existing deck and to contribute to ease of steering and maneuverability.

Century Plaza Towers Descriptive Drawing Figure 2. This Descriptive Drawing of the BMU, is provided for reference to illustrate the various components utilized in in its operation. Note what we refer to as the platform, the component that position workers on the façade, is often referred to as a “cradle”. (click on the image to enlarge)

Century Tower Plaza Towers Figure 3. Shown here in this screen capture from Google Earth, which depicts the unique footprint of the towers.

Sky Rider Newsletter | May 2014 | 400 S. Hope

Completion of 400 S. Hope

Now complete and in service, the Building Maintenance Unit (BMU) on 400 S. Hope is shown here in its final testing operations. With the BMU installed on the rooftop, the platform needed to be brought to the roof by first lowering the wire ropes using manual controls. With the platform rolled into place, the wire ropes were attached and the electrical control system was wired. The platform controls were then used to fully operate the BMU enabling Sky Rider personnel to raise the platform.

Raising the platform to the Roof

Operating the platform over the sloped glass under rooftop control

The fully completed BMU




Window Washing Replacement at AON Center Building

AON Center AON Center In 2008 Sky Rider was selected as the contractor to replace the 37 year old window washing machine at AON Center, LA’s second tallest building at 61 stories and 858 feet in height. The system had been refurbished numerous times over the years, but this would be the first time an entirely new window washing machine would be installed at the uniquely designed building.

The Building Maintenance Unit (BMU) was manufactured by Gondolas in Design (GinD) located in Madrid, Spain. Working in concert with Sky Rider, GinD formulated a design that would work properly with the unusual facade features. As seen in the photo above, the curtain wall slopes inward at the top of the building while the corners remain vertical. This creates the need for a platform center section that moves forward (into the corner) as the platform descends at each of the four corners.

Because of the building height and the congestion of downtown Los Angeles, both a crane and a helicopter was ruled out as means to get the new BMU to the roof. Instead, the machine was designed to allow bringing it, in component parts, through the building using the freight elevator to the 61st floor.

Sky Rider installed its temporary crane on the roof to assemble the machine onto the existing track. The location for the crane was selected to enable us to lift the component parts from the 61st floor to the roof (up two floors) over the guard rail and onto the track.

To read more about the AON Center project scope, please click here.

Project Spotlight | Devon Energy Building

Devon BMUDevon BMU with Temporary PlatformDevon Building

In 2013, Sky Rider completed the installation of window washing equipment at the Devon Energy Corporation Headquarters. Located in downtown Oklahoma City, the building is an iconic, 50-story, 1.8-million-square-foot office tower, comprising nearly 1.8 million square feet of office and amenity space. Devon Energy Corporation, the largest U.S.-based independent oil and natural gas producer.

The window washing at the complex required a full range of equipment from ground based to roof top mounted davits and sockets to specialized interior monorail systems. Most significant however, is the Building Maintenance Unit (BMU) permanently located in the center of the tower rooftop. Weighing in at 97,000 lbs. with a maximum outreach of 92 feet, the BMU allows service of the entire tower’s facade. The BMU features automated work position indication, digital control through conductors in the wire ropes and an auxiliary hoist. The auxiliary hoist operates from platform controls to assist in glass replacement.

To read more about the Devon Energy Building and to download a project PDF, please visit the project page here.

For more information about how Sky Rider can help you with your building access needs, please contact us today.

Custom BMU in Westwood, CA

Built in 2008, The Carlyle Residences Westwood is a 24 story tower at the west end of the Wilshire Corridor, that Sky Rider became involved with in the early design stages. Due to the layout of the roof and need for a helipad which effectively split the roof in half, two Building Maintenance Units (BMU’s) were originally called for. As a cost savings measure, Sky Rider’s design team, working closely with the consultant and general contractor were able to provide a single BMU system that would travel under the helipad to access both sides of the roof.

The following is the step by step installation process of this unique BMU. [jcolumns inbordercss="1px dotted gray"] Step 1. The BMU was completely assembled and tested in the factory prior to shipping.     Step 3. The track was clamped to the support pedestals and the clamp bolts were torqued in place.     Step 5. Shown here is the base being lowered between the two motorized wheel assemblies where they will be bolted together.     Step 7. The assembly continued by bringing each component to the roof and installing it in its proper place using the construction crane.     Step 9. BMU traveling under the Helipad from East to West side of the building. Two operators are necessary to adjust for tight clearances.     Step 11. Commissioning of the installation includes a complete run-through of the machine at each work position. [jcol/] Step 2. As the BMU was being shipped, the track support pedestals and track was installed by Sky Rider’s Crew.   Step 4. The BMU was disassembled at the factory and shipped to the site in two containers.     Step 6. The boom was partially assembled on the ground before raising to the roof.       Step 8. Underside of the Helipad.         Step 10. A telephone is available for communications at track level to the suspended platform.       Step 12. Final testing of the BMU before demonstration to owner and consultant. [/jcolumns]

Sky Rider Newsletter | March 2014

400 S. Hope Updates

Design specifications required that the Building Maintenance Unit (BMU) does not rise above the existing parapet while not in use. A two part system was required to accomplish this. The first consists of an independent elevator system (Photo 1) and the second is a telescoping mast (Photo 2) as an integral part of the BMU. The elevator supports a section of track that, when the BMU is engaged above it, may be lowered for storage. The elevator is hydraulically operated with two rack and pinion gears interconnected through a drive shaft to keep the assembly level and stable.

400 S. Hope Elevator

The mast also has a hydraulically actuated, telescoping, mast to provide additional height which allows clearance for the platform as it passes above the parapet as it moves into its various work positions on the building façade.

400 S. Hope Telescoping Mast

Photo 3, below, shows the BMU fully assembled and functional. Shown here, on the main track and at full height, the process of bringing the platform to the roof will begin. In future installments this procedure will be highlighted along with further details of the BMU operation.

400 S. Hope BMU

Additional News

Sky Rider is proud to announce the upcoming installation of two new BMU’s on the Century City Towers in Los Angeles. The towers are 571 feet in height and were completed in 1975. These towers have been a famous part of the West Side sky line since their construction. In the 1980’s detective series, Remington Steele, the towers were depicted as their headquarters. Numerous commercials have been shot using the towers as a backdrop and, most recently, The Green Hornet featured scenes in which the towers appeared prominently.

The original window washing equipment, now almost 40 years old, has become difficult to service and is in need of replacement. In addition, the existing equipment only accessed the window wall while the new BMU’s will also allow access to the aluminum corner panels without additional equipment. Stay tuned for photos and updates.

The Towers

400 S. Hope Project

The 400 S. Hope Project in Los Angeles is well under way.  Sky Rider’s crane, the TX50, was installed on its own scaffold to provide additional lifting height to clear the 20’ tall parapet.  An existing davit was used for the assembly of the scaffold and crane.  Track and other materials were later brought to the roof using this crane. Crane 400 S. Hope

With the crane operational, installation of the track on the newly installed support structure was underway. The track installation includes an elevator which allows the Building Maintenance Unit (BMU) to be lowered for storage. Where necessary, a temporary davit support was welded to the support structure for lifting the track sections into place.

Track Being Installed at 400 S. Hope

Follow the progress of the BMU installation on our Newsletter / Blog. We expect to have weekly updates. At the end of the project, we will have a web page dedicated to this project along with a downloadable PDF.