St Andrews Links Blog

Irrigation upgrade: The Castle Course pt.2

The main part of the irrigation upgrade was to replace all 635 sprinkler heads across the greens, fairways, semi-rough and driving range. Like the pipelines, we tried to make an early start by digging irrigation heads in out-of-play areas such as the range and turf nurseries. This gave us a head start before we closed in November 2017.

Sprinkler installation in a little over 2 mins!

The process broken down into 7 stages:

1.) Lifting the turf

A frame was made so each hole dug was consistent to the last. The centre of the frame was placed over the existing irrigation head allowing enough room in all directions to excavate around the pipe work. The frame was squared up to the centre of the green so the new irrigation yardage plaque would also sit square to the hole.

2.) Hole excavation

Each sprinkler was excavated to find the direction of the Triple Swing Joint (TSJ) which was then followed down to the main pipe. This allowed us to do a health check on fittings. We found a few were leaking!

Triple swing joint

A colour coded flag system was used. Notes were written on the flags to identify if the irrigation head had leaks or a wire had been damaged during excavation.

3.) Installation of new sprinkler

The pipe work needed to be de-pressurised and the TSJ then assessed for height. A sprinkler comes with an outer body and an inner section called the ‘riser’ – this has the nozzles in it. The inner section is removed and placed in the new outer body. During the changeover of the sprinkler, it’s important that sand doesn’t contaminate the threads of the pipe or sprinkler itself. This could cause a leak in the future.

Cleaning the pipe work threads

New Infinity sprinkler being installed onto the pipe work

4,) Electrical testing

Each sprinkler has a cable running to it so it can be controlled by computer. Due to lightning strikes in 2008 and 2017, some of the wires had become problematic so each cable joint was tested.

Equipment testing

5.) Connecting the decoder 

Heavy rainfall through the winter caused the excavated holes to fill up. These needed bailed out before doing any electrical work followed by checking for leaks in the new pipes and irrigation heads.

Each sprinkler has a decoder at the head. These have an individual code that relates to that sprinkler on the course, so when a signal is sent from the computer it knows which is going to work.

Wiring up the Infinity sprinkler

Once an area was completely re-wired, we tested to make sure the computer was reading the correct sprinklers and all electronics were working.

6.) Back filling

Having dug 635 holes, they all needed to be back filled which was done in two stages. The soil is heavy at the Castle, so instead we used a slightly sandier soil for future digging purposes. This was filled up to the bottom of the sprinkler making sure it was compacted in stages. The sprinkler was checked to make sure it was level and the rest of the hole was then back filled to the surface. Rootzone material was then added in stages and left ready for turfing.

7.) Turfing

Final part of the job was to re-apply the turf.

Throughout the job we used a map with all sprinklers marked using a colour code system so we knew exactly where we were during each stage of the process.

The first holes dug on the turf nursery started on the 25^th of October and we put the last piece of turf down on the 31^st of January. A total of 14 weeks to complete this part of the project!

Look out for my final blog in this three-part series next month… will everything work!?

• Read part 1 here.

Words by Jon Wood, Course Manager – The Castle Course