Kings Development – Dirt Work

Dirt Work

The other major activity in addition to the fencwork, is the actual diamond itself. In an ideal world, this is a fully cut-out infield which would include not just the home plate area and the mound, but also the whole area from 1st to 3rd base. If this is feasbile both from a usage, contrstruction, maintenance and cost point of view, then it would always be recommended. The big advantage of having a cut out infield, is that it provides more consistent bounces of ground balls, the lack of which i.e. when playing on grass, is probably one of the biggest obstacles to getting players, especially young ones, to learn the correct technique for getting their body behind the ground ball.

However, due to the extra cost, and in this country, the fact that many grounds are shared with other sports then it is most likely that the diamond will be limisted to 5 cut out areas, with 1st, 2nd and 3rd bases, being effectively quarter circles, with an additional strip, along the radius part of the cutout (so that the base is not right in the corner of the cut out). It is with this assumption that the rest of this article focuses, although much of what is stated, can also be applied to a full cut out infield, by scaling up.

Marking Out

Just like planning, this should not be something that is overlooked or undertaken lightly. Assuming you are confident exactly where your diamond will be sited, then begin with home plate / pitchers mound / second plate, and ensure the middle of each of these is a line that is exactly half way from both sides of your fence. That will ensure that your diamond is not slightly askew. Once you have that, obtaining the locations for 1st and 3rd base, becomes much easier. Remember, the actual bases for Home, 1st and 3rd, all sit within the diamond i.e. the corner of the base, sits in the corner of the lines. However 2nd base does not. It straddles the point where the lines from 1st and 3rd base meet. Also note, that when marking the actual lines on the diamond, there is no actual line marked betwen 1st and 2nd or 2nd and 3rd. That said, we have found it helpful to do so for training purposes, esepcially with younger or newer players. But it is not a requirement.

We would suggest the following tools are used for marking out a diamond (square), that is exactly 90 ft on all sides:

  • String line
  • 4 pegs
  • 50m tape (useful to measure the 127 ft distance across the diamond, not just the 90 between bases)
  • a second tape (which is helpful when enuring a point is equidistant between two others, and also for getting 90 degree angles)
  • Carrots (tuft markers)
  • Spray paint (for temp markings)
  • At leaste 3 people (to speed things up)
  • Rubber mallet (if ground is hard)

Cutting Out

Although it could be done by hand (spade and shovel), that is really only viable for a single base, unless you have a very large number of volunteers. So we would recommend hiring machinary to do the job of cutting out the first areas and also digging down sufficiently deep enough in order to put some foundation to help with drainage. So we removed the grass and went down to a depth of 15cm, to allow for 5cm of foundation and 10cm of dirt mix. To carry this out, the following items were hired:

  • 1.5 ton digger
  • 3 ton dumper (helps with removal and is also used for filling in with the new dirt

Although you can drive the digger yourself, unless you are experienced, you run the risk of not only having an uneven edge, but also an uneven base, which will just eat up more dirt when you are filling it. It may not seem like it, but it is a skilled job. We would recommend hiring someone to help with this, who has the relevant experience with diggers. Anyone with a bit of practice can drive the dumper, but you will also find a good digger operator will also be able to help with the filling of the dumper so that you can transport the dirt mix to the bases. It is not recommeneded to hire a turf cutter to remove the initial layer of grass, because unless this is done at exactly the right time of the year, then it will either be too hard and will crumble, or will be too wet and will dig in. A digger does a better job.

One thing that must be taken into account, is disposal of material that is dug up. We ended up with a lot of turf, and you will need to hire a company to come in and take this away. A grab lorry is what is requried, and you should allow around £300 or more for this, as you will have to hire the grab loader and then also pay by the tonnage.

We also had to dispose of an old artificial cricket wicket, and this also had to be disposed of separately, although not something most will have to worry about. But basically don’t overlook disposal costs, as they are not minor. Fortuntely we could use some of the dirt coming out of the base areas, to backfill the hole left by the artificial cricket wicket, and additionally some of the gravel of that wicket, could be used as foundation in the bases, saving on some of that aggregate.

The Dirt Mix

To fill in the bases, you need a foundation mix, and a dirt mix. The former is just an aggregarte that is quite coarse and lets water drain through it. Typically know as MOT grade 1 mix (if you go to any aggregate supplier, they will know this) and it is apparently better (and cheaper) than ballast, as it has a wider range of particle sizes. On top of this, goes the dirt mix, and this is subject in itself. Suffice to say, the best baseball dirt mixes, have a certain ratio of Sand:Silt:Clay. Too much clay and it becomes very sticky in the wet. Too much sand it it is just too loose to compact. The document below, is a good guide, and from this, you can see it is something in the region of 70:10:20

Infield Mix (2015)_DRAFT

You could go to suppliers and ask for them to make this custom mix, and it was one option we thought of. But in this country, Bourne Amenity seem to be used by many, and some years ago, someone gave them a mix to make up, and Bourne now know this as the “Baseball mix”. It is very good, as just the right mix, grain size, grain shape and so on. So much easier to there and ask for that. It isn’t cheap (about £110 per tonne) but then most custom mixes are not, and even basic aggregate is around the £50 mark (at time of writing). It also has some finer material in it, that gives it a good colour, which is not something to completely ignore.

One important point to mention is that dirt, whether the foundation or the baseball mix, needs to be compacted. This therefore has an impact on the amount you need. It is relatively straight forward to work out what volume a certain area that is 15 cm deep, is. But you have to take into account that any aggregate when compacted with a wacker plater (another item of hired eqpt), will compact by between 50% and 25%. We found it to be nearer the 25% mark, but had assumed 50%, which is the guide various online sources quoted. So we ended up buying too much, although at least it gives us excess for future maintenence. As we were also constructing the diamond during the very hot summer of 2022, when rain was non-existnent, we found that no matter how much we watered it, there wasn’t enough moisture in the aggregate to compact properly. It only did so, once the summer came to an end, and the rains returned.

Unfired Clay Bricks

Another area where we struggled for a long time, was exactly what to construct the areas of high wear (batters and catchers boxes and top and front of mound). US websites always mention Green Clay bricks, which are basically bricks that have yet to be fired and thus hardened. Might seem simple enough to locate a supplier in the UK, as obviously all brick suppliers need someone to make them in the first place, but the only one we found, and which we know other teams use, is JJ Sharpe in Devon. They do a pallet of bricks (about 400) for about £550. This one pallet was sufficient for the aforementioned boxes and mound. Definitely worth investing in, as I’m sure you are aware of the typcial hollows that most right handed batters and catchers have to put up with, as well as the tunnel that pitchers like to dig at the front of the pitcher rubber. Clay bricks won’t completely stop this, as they will still need maintaining, and will eventually have to be replaced. But they will slow it down.

Carrying out the Work

The actual work in theory is as simple as mark the area out; dig out the hole; put in 33% foundation and then 66% baseball mix, and then compact. But there are some useful lessons we learnt when doing this

  • Compact as you go i.e. don’t put it all in one go, but a few cms at a time, water and then compact, and repeat (hire two compactors – it’s faster!)
  • Ensure you put in more than you think so the the areas are slightly prow to the ground
  • Use a spade to get a good neat edge to the cut outs
  • Some say to put a membrane between the earth and the aggregate to prevent weeds. We didn’t and a good weedkiller seems just as effective


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