The need for bunker liners is a result of poor design

[Mark_Fine]

I was taught long ago by a very knowledgable contractor that, "a dry bunker is generally a good bunker" and "if a bunker is designed and built properly with the right amount of drainage, it will have little rock migration on the floors, no standing water, and very few washouts".  There is no question that he was correct.  I also recall many years ago talking with my friend Matt Shaffer at Merion complaining about the liners in his bunkers.  He stated to me that if the bunkers had been built properly that they never would have needed liners and all they did was cause him and golfers more problems. He couldn't wait to get them removed.

I avoid liners if at all possible by putting in more than adequate drainage and carefully managing the design and construction but sometimes the Super demands them and like in most businesses, "you need to listen to your customer" as they are the ones paying for the product and who have to maintain it.

[paul cowley]

Forest Forest Forest...those of us knowledgeable in the business call this the angle of repose, and a bunker should always be filled at least to this angle. Look into an hourglass if you want to study this effect. Stare into the the glass for a full cycle to really appreciate how this works. It will be good for you, and help calm your mind. A glass of wine will help as you watch. Joking   

[Mike_Young]

The Better Billy Bunker is pretty good stuff .

[paul cowley]

Good advice from your friend Mark. Old school works just fine if done right. I have also learned a lot from a designer/builder, Bob Spence, who learned from George Cobb and others from that period. He built the first courses on Hilton Head...Port Royal and Shipyard, back in the days when they would take draglines out in the marsh to pile up enough fill to create a fairway...in the marsh! Bunker drainage was very important when your fairways were 3' above the water table and working in marsh muck.


We (the Love brothers) have designed many courses with differing bunker styles...Raynor, Ross, or a mix we call Rossnor. In gravelly or highly erosive soils we might favor grass or half grassed faces. In the 30+ courses I have built I don't remember any complaints from superintendents...in fact it's usually the opposite. Now I'm starting to sound like an old timer  , nuff said.

[paul cowley]

The Better Billy Bunker is pretty good stuff .

I've never used it Mike, but will consider on your advisement...price and how its used please?

[Mike_Young]

Paul,
Jerry Lemons can tell you all about it.  I think it's expensive for many places but if you got to do something like a liner it seems to be the way to go. 

[Anthony_Nysse]

When we renovated bunkers in 2013 at Pine Tree, we DID NOT install liners. For those that know, PT has some steep bunker faces and of course, FL summer rains. We were strict with the contractor to direct the water around the face of the bunker and if the water can in at the bottom of the bunker, so be it. That's what the drainage is for. There was a 1-3% slope from the bunker face to the green, directing water around. Other than the 22" rain we had in January of 2014, we never had wash outs. It can be done.

[Mark_Fine]

I actually didn't see the post from my good friend Forrest when I made mine!  We agree on a lot of things but what I like about Forrest is that he knows I am right when we don't   

[Pat Burke]

Played Oak Creek in Irvine, Ca in US Open local qualifier.
Club got snagged in bunker liner in 9th green liner.
Screwed my radial nerve up in my right arm.
Damned thing was less than an inch below the surface

[paul cowley]

Well my informal tally (from my memory) of the responses have been - no one with high praises, have to have them - might be good in some situations, but not all the time  - don't really like them, or see the need, but will install to suit the clients needs - don't like them, prefer to go natural.


Kind of what I would have guessed. I was prepared to get into the design/layout/site conditions of a hole that required the need for liners...along the line of:...if you feel you really have to have them in a certain situation, you might want to think twice about how you could design the hole/bunkers differently...and then choose option B. Mike and Peter covered this early on. Good design is about weighing different options and then choosing the right one.


IMO

[Jeff_Brauer]

Paul,

I agree in general.  If we as architects check the sand for angle of repose, design to keep all upland flow out of bunkers, limit slope in sand faces to below the angle of repose, etc., it reduces the need for bunker liners. 

I like to flash sand up enough to see the sand in the bunkers. I don't like seeing just a grass face.

Here in DFW, I have measured several sands typically used in bunkers, and we can limit wash (except maybe in a hurricane rain) with max slopes of 12-17% with most sands.  That Arkansas white seems to be stable at more slope.  But, that lower slope seems to allow most bunkers to be visible.

That said, I have seen clays migrate up with no drainage, and rocks migrate up in some situations, which I doubt design can overcome.  If you figure the cost of bunker liner vs. redoing the bunkers twice as often to fix drainage, the long term costs may be about equal.

[paul cowley]

Jeff - I agree and BETTER than good drainage is a must. One of my major concerns with liners is after they are installed it becomes more difficult to make changes and adjustments that  need to happen as a bunker matures naturally...whether through maintenance, site conditions or just plain aging. I like flexibility built in. I wish I was good enough to be able to say when I'm done with a design that "this is perfect and I want it to stay so...forever". I've said before that the only thing constant in golf design is change....and it's how you handle it that's most important. I strongly dislike multi grass species combined on a hole for the same reason...bent grass greens with zoysia fairways and bermuda rough, that type of thing. Huge ego at play here. Plus I like natural and liners aren't.


I've been referred to at times as an 'out of the box' type, which is fine by me. I might be outside but I'm out here with a purpose...I'm guarding the box if truth be told. 

[Mark_Fine]

Proper drainage!  It is one of the fundamentals and secrets (and it really shouldn't have to be a secret) in most every aspect of good course design.  Get the drainage right in a bunker and 99% of your problems are mitigated. 

[Scott Furlong]

With Kyle Phillip's direction we just changed all of our bunkers (2, 5 and 6 fairways and bunkers are totally different) at Robert Trent Jones Golf Club.  When Kyle built our short game 3 years ago we tested the top 3 bunker drainage systems.  We decided to install the Better Billy Bunker system and SF35 (angle of repose 35 degrees) sand during this project.  We  had 5 washout rain events (old bunkers would have washed) in June and none of the sand moved.  From prior labor tracking, we historically spent 5K per washout to pump, push, shovel, raked, tamp and rake again.  Furthermore, the cleanup took 1-3 days...then you could say they were bunkers again.  Soooooo for 3 days members and guest had to play through washed out sand ponds followed with days of milkshake/slurpee sand conditions.  If Better Billy Bunkers are considered a liner then mark me down as loving liners. 

[David_Tepper]

http://www.billybunker.com/

[Jeff_Brauer]

Proper drainage!  It is one of the fundamentals and secrets (and it really shouldn't have to be a secret) in most every aspect of good course design.  Get the drainage right in a bunker and 99% of your problems are mitigated. 

Mark, I agree, but here in the black gumbo soils of N Texas, it seems fines migrate up if water puddles at all.  I generally install a little riser, so they can take the cap off and speed up drainage. Never had much luck with those "magic boxes" at the low spot.  Even so, if it stays damp, without liner, soil mixes with sand in 2-3 years time.

[Joe Hancock]

There must have been an RFP put out somewhere for a golf course with no bunker liners....is it in the USA?

[paul cowley]

Jeff - with all due respect I would not design a bunker whose base is in the puddle zone...ie an area that is too low to allow for rapid evacuation of water. If the area can't accommodate a bunker floor with a drainage system whose base slopes are step enough to move  water out rapidly...I'd keep moving it up higher...or choose a different bunker strategy.


I'm researching and warming to the billy bunker system, but its probably something I wouldn't spec for a new design. If I can't harness gravity to do the work (who works for free)...I'd take a pass and move on to a different design option. I'm not a big fan of wet diapers. 

[Mike_Young]

Paul,
I think we both agree that if deep deep sand had not been a natural occurrence in early golf courses we might not have bunkers today.  Also, bunkers are so over the top with maintenance and constrcution cost and can be so well maintained  that they have become a target for many good players vs unknown lies in long grasses.  So, in modern golf the bunker is often there to offer a contrast in color and aesthetics more than a hazard. 
Tr this sometime if you have a fairly flat bottom bunker with grass faces.  In Costa rica I have used 6 inches of gravel with 8 inch perf and have placed 18 inches of compacted sand on top.  We rake the top two inches of  sand and have had no major problems for almost 14 years.  We get a lot of rains during the rainy season. If rocjk ever comes thru then we will decide then how to fix it....i tcan't be that different than a naturalsand site...

[Jeff_Brauer]

Paul,

I agree, even if sometimes the base of the bunker is built up to allow adequate pipe flow and slope to the appropriate drain outlet.  However, all bunkers are built to hold water, because otherwise, the sand would wash out the front....

So, the tile must be big enough to drain it out quickly.  I usually use 6" tile at the bottom for more capacity.  In budget cuts, owners and contractors will point out that others dont' use 6".....but then, others may not have measured the amount of drainage really required, especially after some sand reduces pipe capacity......and I rarely put bunkers where they easily flood.  If you played La Costa this year, you probably noted that the 18th hole had a church pew grass bunker in the flood zone, for practical maintenance reasons.

But even with all of that, fines can migrate up and clog tile, especially if it drains too slowly.  I played one of my courses this weekend where I didn't even put a closed cap on the drain outlet at the bottom - I ran a riser and left it with an open grate so they didn't have to rely on the super to go out and take the solid lid off.....

Cheers.

Cheers.

[paul cowley]

Mike we're singing from the same sheet my friend...sounds like a great gravity system that could easily be extended even deeper if the normal rainfall conditions were greater, or if the soil conditions were piss poor. I will use it...the Better Mikey Bunker System....royalty free?

[Tom Kelly]

In Costa rica I have used 6 inches of gravel with 8 inch perf and have placed 18 inches of compacted sand on top.  We rake the top two inches of  sand and have had no major problems for almost 14 years.  We get a lot of rains during the rainy season. If rocjk ever comes thru then we will decide then how to fix it....i tcan't be that different than a naturalsand site...

Is this 6 inches of gravel in the drain line or over the entire floor of the bunker? Almost like a green construction?




Either way the amount of sand and possibly gravel sounds extremely expensive. Though I don't know the going rates in Costa Rica!

[Alan FitzGerald CGCS MG]

More than once in the previous posts it has been mentioned that drainage is key. As such, I think the point of the porous liners is somewhat missed here. Whether it is Better Billy Bunker ('glued' porous stone bed), Matrix (porous asphalt) Capillary Concrete (porous concrete) or Blinder (porous crumb rubber), they all create a drainage layer in the bunker, helping getting the water to the drain lines as quick as possible, which prevents washouts. The binding material in each just stops the drainage substance from contaminating the sand. The added benefit is that they prevent contamination from stones, silt etc working their way up from the underneath. The older fabric liners had no real drainage properties so were limited in their longevity. 


So to answer the title - A bunker can be designed to minimize liners (ie the liners I mentioned above) but it is not necessarily as simple as saying that if a bunker needs a liner it was badly designed. For example I just rebuilt a bunker that had a large face but after a big rain, barring a few little rills, never washed out. It was still in a bad state as it was full of stones that had worked their way up from the base. It was far from a badly designed/built bunker but it needed help and the liner was a solution.


I've experimented with different construction methods and liners over the years. As mentioned, drainage is very important as is making sure water is diverted away from the bunker in the first place. After that comes the bunker shape/design. If the bunker is designed to have flashed sand it needs to be designed so the sand can naturally stay on the slopes. However after all that is correct, depending on the environment there can still be potential for washouts and contamination from below.


A personal example that design alone doesn't necessarily help is when I tried using a sod liner a fews ago. The bunker was reshaped. Once the sod knitted it looked like it was going to be a winner. However after it was filled with sand for a few months I found that, while the sod held up great on the floors, it 'wore' away on the faces that saw water - so while it worked in one scenario it didn't work in another. The porous liners greatly eliminate the risk of failure and are a permanent solution that greatly increase bunker longevity.


The USGA states the life of a bunker is 7 years; the porous liners greatly extend this as the sand does not get contaminated and continues to perform as it should. As Scott stated, the savings in labor and replacement material in repairing damaged bunkers makes the decision to install them a lot easier and that's before the downtime/inconvenience of the repairs are considered.


Due to the amount of variables in bunker design and the environments they are in, to blankly say liners are the result of bad design is misleading.

[Mike_Young]

Alan,

Nice piece.  All of those methods you mention seem to be the new " in thing" and I keep hearing this blinder system may be the ticket.  I think it explains the bunker situation well.  But it also makes me realize how far we have come since the first bunkers and how we have killed the "golden goose".  The money clubs are willing to spend on bunkers today is a cost that is not necessary at all for playing the game as it was meant.  And it sets a standard that public facilities and developers feel they have to match to be considered standard.  But then I guess we could say the same for each line item.  Again nice explanation..are you a supt, construction or archie?

[Alan FitzGerald CGCS MG]

Alan,

Nice piece.  All of those methods you mention seem to be the new " in thing" and I keep hearing this blinder system may be the ticket.  I think it explains the bunker situation well.  But it also makes me realize how far we have come since the first bunkers and how we have killed the "golden goose".  The money clubs are willing to spend on bunkers today is a cost that is not necessary at all for playing the game as it was meant.  And it sets a standard that public facilities and developers feel they have to match to be considered standard.  But then I guess we could say the same for each line item.  Again nice explanation..are you a supt, construction or archie?

Thanks Mike


I'm a superintendent and I'm also the US licensee for Blinder, so inevitably have become a bunker expert over the last few years.


You're right; when you look at the fact that bunkers are hazards and the amount of maintenance they now require, it certainly can raise eyebrows, especially at a time when the USGA and R&A are pushing sustainability. However as you mentioned it is just a part of each standard being raised. Look at greens speed and performance - even the "worst" greens now would have been acceptable at high end clubs 20-30 years ago.


One trend Blinder in the UK have noticed is that it is not just the 'big' clubs improving their bunkers. The smaller clubs see the value in redoing their bunkers to a high standard that will remain long term. While they may not have the resources to do them all at once, the value of fixing them over time is worth the benefits of reduced maintenance and repair costs, along with better conditions for their players. Based on that, I guess indirectly these liners are sustainable if courses do not have to replace sand over time and the benefit of reduced maintenance/costs to have bunkers play at the conditions now required.

Of course in the situations where you can get away without them, even better!