Speed run course at the Diversion

Our Speed run course at the Diversion
By Nitro Ned
Some history
The course was first set up for stopwatch timing using 2 sight poles on the North bank and a sight board on the South bank.
The sight board was a 1.5m X 250mm board painted white with a 50mm wide black line painted up the center and this was mounted in a concrete plinth

The distance between sight poles and sight board is approximately 200m so the black line appears to be about 3mm wide when sighting thru the poles.
The poles are 3/8 steel rod and 10m apart. Also mounted in concrete plinths.
The rear pole is used to align the front pole with the vertical line on the sight board and once done runs were done just sighting front pole with sight board.
The course was first set out in 1990 by myself with the assistance of Fulton Hogans surveyor using a robotic total station.
In 1993 we got a huge flood in the river that took out the front plinths on the North side so got Mort from Gilbert Hames and Associates to re-establish the front plinths for 2 boxes of beer!!
I then personally checked the course using GPS surveying gear whilst working for Morris Contractors every 2 years using a 5minute fix on each point.
The north side always came in at 100m exactly whilst the south side always 100m +8mm so it was 8mm longer than the required 100m and trying to get it 100m exact was really a waste of time and a big job moving and re-pouring a new plinth.
For several years after leaving Morris contractors the course never got checked then we had the Kaikoura earthquake.
Being now involved with river protection for the MDC and seeing the destruction to some of the stop banks within 1 kilometer each side of our site, I decided to again engage Mort from Gilbert Haymes to recheck the course Before we did any more speed runs for 2 boxes of Heineken!
Interestingly the South Side had stretched to 150mm longer than 100m and the north side now 50mm longer.
We ran 1 set of speed runs using that set up prior to setting up for laser timing.
LASER TIMING
Carl Hansen kindly donated 2 sets of laser timing gear to the NZMPBA. 1 for the North Island and 1 for the South Island
We needed a mounting system for the laser on South side and receiver on North side over 100m apart and the beam must be set up no more than 100mm above the water to capture our boats. Needed to be adjustable both up and down because we are tidal where we are and left and right.
I went with Alloy angle brackets with mounting holes in 50mm increments for laser adjustments up or down bolted to driven Railway irons.

upstream(west end) receiver bracket up stream laser bracket
Fortunately for me Simcox Construction has a digger set up for driving such irons and the Operator is one of these pedantically fussy people about getting things perfect, so we got 4 x 6m irons donated by Simcox delivered with the pile driver.
The weekend before Ant Schroder, Marie and I went down to set out pegs close to the edge of the bank for setting up the total station when we drove the irons.
I set up over the downstream sight pole hole and lined up on the center of the sight board and locked the station. Ant drove a peg on-line and then with a biro I was able to get him to scribe a line on top of the peg exactly on line.
To make a correction for the over length he drove another peg up stream beside that one and scribed a line on it 140mm from the original peg using a tape measure then removed the first peg. We now had a set up peg for the total station on-line when we drive the north side railway iron
On the west or upstream end, we set up on the front pole end as before and Ant again put in a peg online for sighting purposes.
Now on the north side we drove a peg online and a second now 50mm downstream so we could remove the 50mm over length on that side.
Pile driving day I set up total station on south side peg, sighted onto the sight pole to get the line then using a combination of a spirit level and total station was able to get Gordon to drive the iron spot on with the Centre of the iron bang on line.

Total Station North Side East end
I then relocated to the west end on south side and repeated the previous procedure.
Whilst Gordon was relocation to the south side I set up on the North side and repeated what we did before for the south iron on the east end.

South side east end South side west end
We relocated to the west end and it was this last iron that gave us a bit of grief. We hit something pretty hard half way in that put the bottom of the iron a little off line up stream so we did not get it quite vertical which of course annoyed Gordon immensely as it was not perfect but I assured him on the radios that we can correct it when we bolt the brackets in place.
Mounting day with Ant again armed with generator drill and G clamps total station and a laser level.
I was able to set up the laser level so I could see all 4 irons and using a rod eye and vivid was able to scribe a line on all 4 irons at the same level. We now had a level height to work to on all 4
Using the total station for line we lined up a bracket dead plumb on-line and the correct height to cater for a low tide measurement (we had done checking on several occasions in advance.) Using G clamps to hold the bracket we were then able to drill 6mm holes to bolt the thing to the iron.
We repeated the procedure for all 4 irons and was able to make the adjustment and get perfectly plumb even on the bent Iron.
SETTING UP THE LASERS
I had to come up with an easy way to mount the laser and receiver to the brackets and all be exactly the same.
I searched the workshop and found 4 Zenoah back plates that come with new motors which we discard when we fit engine mounts. As luck would have it 2 of the holes lined up perfectly with the units but too small so clamped them together and drilled the holes out to 6mm for mounting bolts. 1 x 6mm bolt and wing nut was mounted in the centre of the plate on other side for bolting to the bracket

Down stream receiver. laser pickup on bottom, light telltale on top
Each receiver is housed in a wood shroud (pictured) to stop the sun shining on the RX face and upsetting beam. Info gleaned from the Aussie boys
The lasers uses a red beam and having worked with red beam pipe lasers knew it was going to be hard to see the bean in daylight so we planned to have a go at lining things up on dusk when we had a suitable low tide.
We tried with Ant guiding but could not even find the beam on the receiver side so had to wait till it was dark then found it. And our first problem. Un like a pipe laser that had a powerful dot 20mm in Dia at 150m this one is 200mm in Dia and substantially weaker.
Next day at low tide painted the irons white and hunted down some polystyrene sheet to wedge between bracket and iron to make the beam stand out. That night managed to get both lasers shining onto the receiver poles, so the laser brackets were now on line.
We now had to get the receiver brackets on-line to pick up the laser so next night mounted lasers to receiver brackets and brought them into line as we did the night before.
Now the next test, to get the beam lined up with the receiver. Another night mission with everything powered up. The units will work on anywhere between 12v and 240v so 2 x 14.8 lipos on the receivers and 2 x 22v lipos for the Lasers did the trick.
How they work. You power up the receiver first and the telltale light comes on.
Power up the laser and when it comes online the telltale light goes out. Break the beam and the telltale comes back on till it picks up the laser and goes out again, so you know if the laser is not lined up perfect the light stays on. Simple aye or so we thought. Got em all lined up and going so happy we had things working.
Next day in daylight thought a piece of cake to get things going as we had it lined up the night before, so in same bracket holes as night before and the telltales are on. Tried finding beam but fruitless in daylight. Back down again in the dark and lined things up again. Then to see what was going on unbolted laser took it off then bolted it back in the same hole and it was out a couple of hundred mm. it was then we discovered that the slightest movement on the laser had a large effect on the receiver side. The over tightening on the wing nut for example would move off the receiver then back off and it would come back on.
Dam we need to come up with a means of lining things up in the daylight.
Few days pondering then back to the construction industry. In recent years pipe laying lasers have started coming out with a green beam as it stands out much brighter than the red in the daylight. We need a green beam laser.
Come in Wish. I found some 1000mw laser pointers that might do the trick so with nothing to lose got a couple for 20 bucks.
After they arrived down to the Diversion in the daylight and whippee could pick the beam up as clear as day on the white Irons. Now to come up with a mounting system and came up with this below.

Clamped a Zenoah bracket to the plate and drilled holes thru the plate so the laser would be set up the same. Drilled another mounting hole 100mm above so we now had 2 points of contact then mounted the green beam with a threaded U bolt.
Another night session armed with shims and spanners, first lining up the laser
Then using the shims brought the green beam into line roughly 300mm above the red beam. Boy at night those green beams are incredibly bright. No wonder pilots get toey when they get flashed by one.
Over 12 months have gone by now so was keen to give the system a run having had it set up on the lounge floor to figure how it works a couple of times.
The event timer box runs off a USB port either manually with a suitable power supply or off a Laptop.

Event timer and beeper laser set up
With just a power supply you must record the run times manually but with a lappie and their program everything can be recorded electronically and the moment the timer stops, the speed for that run is displayed on your laptop screen.
I managed to score a Ryobi 1600watt inverter generator for $1200 at Bunnings to run the laptop then needed 120m of 1 pair cable to run from the receivers to the event timer. 110m from the top end and 10 m for the bottom end. Because the system runs on low voltage we needed a good quality cable so consultation with a guy at Cory’s recommended hi-fi speaker cable.
We selected one that will fit into the clip plugs on the timer that cost just over $20 a meter. ($240 all up).
Set up plugs etc. for receiver ends and purchased an electric fence reel to wind the long cable on.
Down to set it up for some trials for the first time and hooked up the cables after lining things up and did a couple of runs and things seemed to work for a start then the top end started auto tripping by itself. No attempt seemed to be able to stop it so back to the drawing board. Another problem was that the upstream cable was lying in the water coming out the Pukaka drain and it was catching weed and trying to float out into the river. We needed to also come up with a plan to keep it in the air. Solved by running a wire across and cable tying small carabiners to the cable and now it was up out of the water.
The auto tripping was still a headache, so another night session then suddenly dawned on us what the problem was. The beam is 200mm in dia at the receiver and it must be 100mm above the water. I discovered that if the receiver was at 12 o’clock in the beam the bottom of the beam was touching the water!!
Soon as it started to ripple with breeze etc. it was causing it to trip.
Now when we set up, we must make sure the receiver is at 6 o’clock in the beam and no more auto tripping.
First official runs using lasers 3 March 2019 and went without a hitch other than you don’t know if the clock as started and stopped unless the one manning the controller says so.
Carl Hansen came down for some runs in August and he also mentioned you don’t know when the clock starts and stops if the timer does not mention it as well.
Having view Jorgs world record 200mph run in Germany on YouTube a few times I noted they had a beeper go off when the beams were broken mentioned it to carl and he sez he has the man in Whangarei that can do that as well as better plugs for connecting the cables to the timing unit. So, he took the unit back got the work done and sent it back to me.
Now its brilliant the moment a beam gets broken the beeper goes off. Then you know if there is auto tripping going on or like on our last runs a blue heron broke the beam when it walked past the laser on the south side and then later that morning low flying shags did as well!!
HOW IT WORKS
We launch and head down stream about 250-300 meters turn and head up stream and the timer screen looks like this

The arrow tells us the left beam starts the clock and the right beam stops it. The moment the clock stops the time and speed is displayed on the laptop.
While the boat runs up and turns around for the return run the operator touches the arrow and the timer should look like this and we repeat above.

You must average the 2 runs manually to get the correct 2-way pass.
Touching the arrow, a 3rd time brings up the 2-lap screen for 2 lap oval timing

Touch the 2 lap and it returns to top screen above.

So, there you are. No human error any more with stop watches this set up is instant and you don’t need 4 timers any more just 1 person to work the timer unit. They can also launch the boat and official observe as well so in reality 2 people are only now needed to do speed runs here.

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