Arena models (2) – raising stairway

This second model will be used for integration into videos as for the first (ramp) model but, in addition, model details are planned to become “stars in their own right” — showing what the audience never saw behind the scenes.


Technology: SOUND/VIDEOmain RAMPSTAIRWAYSoverhead CABLES
Models: main RAMP, STAIRWAY
Main project: return.


MeasureStairs3c

Raising stairways are located at the north and south ends of the arena; the south is more complicated with a vehicle down-ramp from stage level to exit level, and below that is a foot access to the ramp of the LED central stage (for the soldiers for example).

MeasureStairs3

The two main elements are (1) the supporting girder structures and (2) the two-section stairway which provides normal entry (shown in the image above) and very high entry when the two parts are opened together.

DrawingRampEntry

Construction of all these models begins with critical measurements and learning how things were put together, taken mainly from photographic material.  Our video and photographs were taken on 20 or more visits to the construction site, the actual show, and four months extra of de-construction. Published aerial photos shot directly above the arena provide useful macro ratios and dimensions.

DrawingRampEntry.001narrow

Above: Diagrammatic cross-section of the main stage ramp, and position of the rather complex foot access to it.    ⬆

Below: The main stage ramp pit was dug December 2018 then covered up until January: this shot, taken over that holiday period, along with parking space markings as an embedded scale, provides quite accurate size information.  ⬇

Vevey-2019_0101_VeveyRampPositionning

Next images show base of the large south stairway support  (we can just make out foot entrance to the main stage ramp), and to its right a view underneath the stairway construction.  ⬇

Foundation for this model is “ground level” the raising mechanism will be below ground, as will visibly be the foot entrance to the main stage ramp. We begin by precisely placing blocks for the two support structures, as was done very early in the real construction. These blocks are sturdy — our estimate by comparing relative height with the girder structures they support, is that they are each 75cm high and 3 meters long. ⬇

As we researched our photos ready to build the stairway model . .  we uncovered the complex nature of the pedestrian entry to the main stage ramp.⬇ Its necessity became clearer once we realized just how much supporting scaffolding was required to build up the arena seating and stages — we thus believe that the primary purpose of this re-enforced concrete shape was to maintain a clear space and to guide performers onto the ramp — particularly for the 200 soldiers who needed to enter quickly in formation, four across, and with tall staff rods. It looks like this method allowed them to enter two from each side. In one scene, they entered five across – extra complication and not a lot of space on the 4m wide ramp..

The vehicle down ramp is full width of the stairway above it, and integrated with the support girders and arena main pillars. ⬇

DSC01905

Sometimes the model work feels like watch-making ! ⬆
Stairway pivot on the prototype is relatively small and seemingly inadequate – we will see if any similarity can be developed for the model – our pivot is perhaps overly sturdy and imposing, but it works well. 

The heavy steel counterweight  is prepared. ⬇ Each weight of the model weighs 350g (700g the pair), which corresponds to the weight of the combined upper and lower stairways. Each weight is made up from 4mm steel, 3cm x 12cm, a sandwich of three plates. ⬇

It turns out that the tiny supports for the counterbalance weight took more care than expected:

StairwayFrameImage

— Stairway model, construction highlight —

DSC00531crop

“Pistons” installed on the lower stairway – shown above ⬆ in the “down” position. Note the vehicle down ramp under the stairway and also the below-ground level pedestrian entry to the main stage ramp.

DSC00524narrow

Lower stairway “pistons” shown ⬆ in the “up” position. This moment in construction is a special one, being the very first time that the lower stairway is self-supported and to note that the model is very stable with no side-ways movement. This stairway opening height can be adjusted by turning the “pistons”.

DSC00528

Under-stairway view ⬆ showing both “pistons” raised –  still a lot of work to do but already giving some ideas for video integration.


Comparing “north” and “south” ends of the arena.

Our model is of the “south” end which is the more complex of the two stairways. For comparison, here is the “north” stairway construction ⬇ — only two thirds of the south end height above ground level, a very short down-ramp and no beneath stage access. Good structural visibility here during deconstruction of the arena.

NorthStairwayRaised

Technology: SOUND/VIDEOmain RAMPSTAIRWAYSoverhead CABLES
Models: main RAMP, STAIRWAY
Main project: return.