BluehoistBlue
What is the blue hoist? (text from 2009 manual)
The new hoist project evolved out of an identified need for a replacement for the Art Handling Departments existing large picture lifter (termed “the Grey Hoist”). The Grey Hoist was an old (at least 50 years) piece of lifting equipment that was used to move altarpieces and large-scale pictures within the Gallery. Initially, a design was conceived as a copy of the Grey Hoist, only modified and updated. However, the Sainsbury Wing was scheduled to be refurbished for its ten year anniversary in 2001 and funds were made available to the Department for a custom designed solution to the problem of moving altarpieces on and off plinths.
To begin the work, the then three Senior Technicians within the Art Handling Department first looked at possible ideas and attempted to identify the design limits the new equipment would need to conform to. Work then switched to the structure of the display plinths themselves. These plinths had been designed when the Sainsbury Wing was originally constructed and the assumption at that point was that the altarpieces would remain on permanent display in one position within the Sainsbury Wing. Experience showed this was not the case and new plinths, therefore, had to be designed that allowed equipment access to the works themselves. The new design for the plinths, were produced by one of the Senior Technicians in association with a designated engineering company. This design incorporated an internal steel armature capable of lifting the altarpiece when raised (from an external source), these we termed “Ejector Plinths”.
Work on the picture hoist itself then stalled for a period of time, during which the Grey Hoist was modified to bring it in line with modern Health and Safety issues and extend its working life. These modifications proved to be unsuccessful and further modifications, from a design produced within the Department, were necessary to enable the Grey Hoist to continue to be used. However, the extension was only intended for a period of one year and so a new design for a large lifter became essential.
Project Aim
The purpose of the hoist project was to produce and have manufactured a replacement large picture lifter that was able to move large altarpieces within the National Gallery Collection, but also be adaptable for use on other large moves when required. The new lifter should conform to all current and predicted Health and Safety legislation and any further needs that could be envisaged. It should also provide safe and legal access for two technicians at height. The new lifter should simplify the moving of large works and limit the equipment required, yet be cost effective and provide longevity of use.
Design Limits
The main issue facing any new design was the manner in which it could engage with the new Ejector Plinths, yet remain flexible enough to be used where other hanging methods were preferred. The design also needed to deal with the spatial limits and existing conditions in the old and new parts of the building, for example the width and height of doorways, floor loading and storage.
In addition was the problem of moving the Gallery’s large Botticini panel work that hung high over the main public lifts in the Sainsbury Wing. This work was hung significantly higher than any other and a piece of equipment had been designed specifically for this purpose. This though, had proved too large and impractical for the task so was due to be scrapped.
Initial Proposals
The first proposals to be considered centred on two companies asked to look at the problem. These were the lifting platform specialists Planet Platforms and the Stacker suppliers Wilmat.
Wilmat's proposal centred on combining a large forklift from their stock, with a lifting cage of our design. This was rejected on the basis of the inflexibility of the proposal and the need to use Genies in the method. The proposed forklift Wilmat suggested supplying was beyond the floor loading of the Sainsbury Wing, so making the design impractical.
Planet Platforms had supplied the Department with two of our mobile Genies and their initial proposal looked quite promising at first. This involved a bespoke design similar to the Grey Hoist that had been worked up to quite a detailed point by the company’s designers. However, the design did not advance us any further than the original Grey Hoist and the cost seemed quite high.
Due to the specific nature of the task, particularly concerning the design of the plinth, there did not appear to be an "off the shelf" solution. Also, it quickly became apparent that the Botticini move should be treated as an independent problem, as the task involved was significantly different from any other move in the Gallery.
Two further proposals were advanced from within the Art Handling team itself; one involved a simple gantry and lifting tray that utilised the large manual Stacker the Department already owned. The other design involved a composite structure consisting of two access towers and a main lifting body that could be constructed around the Ejector Plinths but stored in three parts.
Project Direction
Further meetings involving the whole Art Handling team were convened to decide on the direction of the project. The consensus was that the design would best progress if it was produced from the internal proposals and would also utilise the experience and skills of the team.
The simple gantry design seemed to offer a quick and cheap solution so this was looked at first. However, there were a number of problems with it that appeared when further work was carried out. Firstly, the design only provided front access to the plinths and work. Due to the distance of the front edge of the plinth from the wall, this meant that a person on the access platform of this design, would have to lean over the safety barriers a considerable distance to steady the movement of any object being moved. Also, the design would have exceeded the set limits in overall dimensions that any Trolley or equipment could have if it was to be moved throughout the Gallery.
However, there were a number of features that could be used. The use of the 1000kg independent Stacker as the lifting mechanism solved a number of issues with regards the complexity of the main body. Weight displacement was also crucial due to the weakness of the floors in the Gallery, so the absence of any hydraulic system on the main body itself was an advantage. Certain other principals were also established such as the need to “register” the main body with the plinths in the same place every lift. Side access at height was also seen to be preferable.
Composite Design
After further discussion it was then decided to adopt the composite design as the main proposal and work started on this in January 2005.
Initially a series of drawings (over three or four phases) were produced by the Senior Technician now running the project. At the end of each phase, the team would take stock of the progress and discuss the developing design. After the second phase it became possible to look further at costing and who would manufacture the design. It was also possible to look at building simple, full-scale models of parts of the design to test the ergonomic performance and get an idea for ease of use.
By the end of June 2005 a final set of detailed engineering drawings had been produced. The design followed the initial concept, there would be a central lifting section that acted as the main body and was also the transport for the object lifted. This would have no access for persons at height, but would be of the correct dimensions to be moved easily around the Gallery. It would have a lifting tray that also incorporated a sliding “fork” system allowing integration with the Ejector Plinths. The tray would not have its own hydraulics to allow it to be raised, but could connect to the 1000kg Stacker, which would provide the lifting power. The main body would “register” with the plinths, allowing the same lift each time. Once the object was at its rest position on the main body then two “picture clamps” would hold the work in a vertical position for transport.
Two aluminium towers would provide access at height, these would connect to the vertical “handles” on the main body and these handles were extendable, so allowing the towers to be positioned either side of the plinth and run to the wall. Together with a further horizontal connecting point at the back of the main body, this provided a stable and secure platform, for one person either side of the object to be lifted.
Outcome
The final design was produced by August of 2005 and the drawings sent to the manufacturer. The Department already had a good relationship with the manufacturer as they had also produced a number of other equipment we had designed, over a number of years. This allowed us to follow the manufacturing process and make alterations if deemed necessary.
The final design was produced and delivered in September of 2006. Once delivered, there then followed a period of “running in” time that included training for the team and making a number of minor alterations to the hoist (as experience informed us). The New Hoist (now termed the Blue Hoist) is now fully operational and has fulfilled the design specifications originally asked for.
Conclusion
As a project, the Blue Hoist has proved to be very successful, completely fulfilling the stated aims. As an exercise, it also had benefits for the team as it allows team members to become involved and motivated by a significant problem that needed resolution. This led to team members utilising skills that they had but could not ordinarily transfer to the work of the Department on a daily basis. It was also an aid to team morale as the successful completion of the project gave a sense of accomplishment in the task.
The project had a cost benefit in that the team were responsible for all aspects of it, so saving considerable fees that would have been required if the work had been contracted out. However, the amount of work required, particularly in the design phase but also in following the production, was significant. The project was also run at a time of some issues regarding recruitment in the Department and this caused a further burden.
The project though, has been of immense benefit to the Department and has also given team members (particularly the Senior Technicians) invaluable experience in Project Management. The result is an efficient, built-for-purpose and economic piece of equipment that allows a vital, but problematic task to be carried out to the highest standard by the Art Handling team.
Advisors to the Project:
Duncan Body Health & Safety advisor
Martin Banasik (Allianz Cornhill) Engineering assessors & insurers
Tony Reeve Panels Conservator