Team Picasso · How we work
“Boille” is our word for the sprayer we carry on our backs. From the hut to the last run, see how we get our kit ready and mark the snow on skis, lance in hand.
The marking team leader looks at the course through a racer’s eyes. Which roll disappears in flat light?
In the hut we check the hose, lance and nozzle. It’s easier to investigate an uneven spray here.
Water carries the blue dye. The hut crew take the temperature into account when preparing frost protection.
One person sprays the curve freehand while the other looks ahead and gets ready to take over.
The pair waits for clearance from the team leader before working on the indicated section.
From the side of the course, you can see a blue curve beside the gates and a short line across the crest of a roll. These marks help racers read the terrain. Each racer chooses their own line.
In the hut we prepare the ‘boille’, our backpack sprayer, and check the spray pattern and radio. During course inspection we identify the gates and changes of gradient to highlight with the marking lead, then divide up the sectors.
Estimate the mix for 100 mOur setting is 3 bar with either nozzle. Very close to the snow, small arm movements show up in the line. Follow the ground over rolls and across the slope to keep the gap and travel speed consistent.
At constant flow, litres per metre = flow (L/min) ÷ travel speed (m/min). Worked example: 1.5 L/min at 30 m/min gives 0.05 L/m, or 5 L per 100 m. To try this in the calculator, enter the equivalent speed of 1.8 km/h.
For the 6504 aimed at right angles to a flat surface, theoretical width = 2 × height × tan(65° / 2). Measure height perpendicular to the snow. Width and height use the same unit. Wind, tilt and uneven snow affect the actual strip.
At 3 bar the reference tables list 1.58 L/min for the TeeJet 6504 used for comparison and 0.93 L/min for the 1.5 mm Duro (28502324-SB). At equal travel speed, higher flow puts more liquid on each metre of line. We measure actual lance output in the hut.
Compare the 6504 and Duro at the same pressure →
Watch the gap between the nozzle and the local snow surface. At a breakover the snow drops away from the hood if your hand stays level. A line across the course brings that change into view.
Look at the strip you have just laid down. Its contrast and the definition of its edges can vary with the surface. The crew judge the need for a touch-up by looking at the mark on the snow.
The hood helps contain the spray. When shadows disappear, look downhill from above the mark, as an approaching racer would, and check that the line is continuous.
On compact snow the dye may stay near the surface. Fresh snow can absorb it or cover the mark. In fog we reassess the visual references with the person in charge. In severe cold the mix must stay fluid all the way to the nozzle. Follow the instructions for the antifreeze product.
The lead marker sets the line. Their partner carries it through from the preceding section. Pairs coordinate by radio in response to the technical delegate’s requests. During a race they wait for a scheduled interruption and clearance from the person in charge before entering their sector.
The lead marker lays down the first line. If a mark disappears, a TV break can provide a window to refresh it. The pair waits for radio clearance before entering the course. Even with identical equipment and pressure, looking back at the result and comparing notes helps volunteers refine their technique.
The simulator shows the 6504 flat fan nozzle. Move a slider and watch the blue strip change. At × 1 you are back at the starting setting.
Volume per metre relative to the reference pass
Theoretical model at a constant fan angle, on a level surface without wind. For the same nozzle, flow varies here with the square root of pressure. Speed affects liquid deposited per metre. Height spreads that liquid across a wider or narrower strip. The simulation gives no on-snow settings.
Crans-Montana
We call our backpack sprayer the “boille”. Its pump feeds the mixture from the tank to the lance.
Our course version of the Birchmeier REB 15 AC3 has a 15 L tank, an 18 V / 72 Wh CAS battery and a charger for 230 V. The whole kit weighs about 25 kg when full. The pump reference and modifications are still to be documented.
The nozzle at the tip of the lance shapes the spray. We use both a 6504 flat-fan nozzle and a round spray nozzle.
Compare the nozzles and estimate spray volume
6504 generally denotes a nominal 65° angle and flow size 04. Pressure and distance affect the width. Skiing speed affects the amount per metre. Still to document on our equipment: the make and exact part number of the 6504, measured pressure and flow for both nozzles, marking width on snow and compatibility with the lance and hood.
TeeJet · PDF ↗The hood surrounds the nozzle and shields the spray from wind just before it reaches the snow.
It helps keep the edge neat and limits dye dispersion. The attachment and compatibility of each setup remain to be documented.
Liquid in the hose can cool down even during a chairlift ride. Insulation slows that cooling.
The nozzle remains sensitive to cold. We check the spray in the hut before setting off. The insulation material and mounting details remain to be recorded.
We favour blue TRAWOSA Color Mark and have also trialled ColourPro Indicator. When the cold calls for it, we add a RIWAX concentrate to the water.
See how we prepare the blue mix
Preparation depends on conditions. Follow the manufacturer’s information for handling each product. Team mixing ratios are undocumented here.
The huts supply the crews with mixture and spares. Sometimes ten Picasso skiers arrive almost at once.
At the Cry d’Er jump, Bertrand looks after connectors, nozzles and batteries. The women’s start has a second refill point and spares. After a repair, the lance is tested before its return to the hill.
When race control requests a touch-up, the team leader radios the pair responsible for that sector.
Radios stay on until the final racer. A TV break alone is not clearance to enter the course. Sector assignments and radio channels are confirmed for each race.
We dilute Riwax antifreeze concentrate with water. A few drops of the prepared mixture are enough to see the boundary between the light and blue fields in the eyepiece. Turning that reading into a temperature requires a scale calibrated for the liquid.
Check the zero point as described in the instrument manual. Place a few drops on the clean prism and lower the clear cover so the liquid spreads without air bubbles.
Look through the eyepiece and bring the scale into focus. Read the appropriate scale where the two fields meet. Clean the prism after use as directed in the manual.
On the dial shown, the windscreen symbol identifies the washer-fluid scale (SRF1). G13 and G11/12 are glycol scales. The battery symbol marks a density scale in kg/L.
We still need to confirm whether the washer-fluid scale matches our dilution of Riwax concentrate. The diagram shows how to take a reading and gives no frost-protection temperature.
The nozzle at the tip of the lance shapes the spray before it reaches the snow. On our Birchmeier REB 15 AC3 backpack sprayer we use a 6504 flat fan and a Duro hollow cone. Here’s how to read their patterns and plan for a race.
Estimate spraying time and mix volume
In the common nozzle code, “65” gives the nominal 65° spray angle and “04” the flow size. The TeeJet TP6504, for reference, delivers about 1.51 L/min at 2.76 bar (40 psi). Actual flow depends on the make, the condition of the nozzle and the operating conditions.
The 1.5 mm Duro-Nebeldüse produces an 80° hollow cone. Most droplets travel along the outside of the cone. As the skier moves, successive rings overlap on the snow.
G1/4″ connection · brass and stainless steel
Manufacturer’s part number 28502324-SB
EAN 7611034100166
Principle diagrams with the lance perpendicular to a flat surface. The patterns shown are not measurements taken on snow.
| Characteristic | 6504 · Flat fan | Birchmeier Duro · Hollow cone |
|---|---|---|
| Pattern and nominal angle | 65° flat fan | 80° hollow cone |
| Catalogue flow at 3 bar | 1.58 L/min (TeeJet TP6504) | 0.93 L/min (Duro 1.5 mm) |
| Liquid distribution | A flat, elongated sheet | Droplets concentrated around the cone wall |
| Distance from snow | Raising the nozzle widens the band. Its orientation follows the lance. | Raising the nozzle increases the ring diameter. |
| Mark while moving | The fan sweeps a band whose width depends on its orientation. | The rings overlap. Skiing speed changes the amount per metre. |
| What to check | Fan orientation, a consistent line and the condition of the orifice. | Cone symmetry, wind and the effect of the spray hood. |
How long will the lance be open along your line? Enter the length of one pass and your average speed while spraying. Only pressures with a documented flow rate for the selected nozzle are available.
A theoretical estimate for continuous spraying at constant speed. Time excludes lift rides, stops and refills. Conditions and the mixture can affect actual consumption.
Time (min) = length (m) × number of passes × 0.06 ÷ speed (km/h). Volume (L) = time (min) × flow (L/min).
In Kitzbühel, Gerhard Raffler recalls trials with Easter egg dye, beetroot juice and berry juice. Residue caused problems in the pump.
Hahnenkamm · 2024 ↗In a 2009 note, Andrew Wolff describes the division of work at Lake Louise. Separate crews marked the course edges and the changes in terrain.
Alpine Canada · 2009 ↗Alpine Canada · 2018 ↗