I got an insider’s look at stadium drains by going to a football game.
Arrowhead Stadium, home of the Kansas City Chiefs, uses a wider breadth of trench drain systems than its sister stadium, Kaufman Stadium, home of the Kansas City Royals.
Heel-proof Trench Drains
Arrowhead Stadium has recently gone through a remodeling, adding a new press area, a founder’s plaza, and a hall of fame. I was impressed with the changes I saw, having been an employee of the Chiefs organization some 35 years earlier. Upon entering the stadium, I headed down to the stairs on my way to the field. At the base of the stairs, I noted Zurn stainless steel perforated grating in a Z886 channel. It was fitting that the heel-proof drain was at the base of the stairs, which would be a collecting point for the rain and melting snow tracked into the stadium from the barrage of pedestrian traffic.
Pro Tip: due to the high pedestrian traffic at sports venues, drain grating is most always heel-proof, if not ADA compliant
That is to say, the open area which makes up the holes of the grate was less than 3/8″ in width. Also, you will see an effort by the architect to specify a slip resistant surface on the grating. In the case of the Zurn Grate, the perforations included some raised dimples which made a gripping action for the soles of a wet shoe. The particular Zurn Grate style is the Z886-PSC.
Making my way to the field, I was able to inspect the field perimeter drain. This drain runs around the field and about 10 feet from the wall stand. This particular drain had galvanized steel perforated grating in meter lengths as is common with the European style products such as Polydrain, MEA or ACO drain. All three of these channel systems are basically identical. I suspect that this particular product was the PolyDrain system due to the lack of brand identification on the grating. MEA and ACO drain tend to put identifying marks on their grates.
The evolution of sports broadcasting has had an effect on the trench drain of this stadium and, I suspect, other stadiums. Originally when this drain was installed, I’m sure the designers envisioned that the loads seen by this grating would be football players, coaches, security personnel and maybe a golf cart of some sort.
Now-a-days, there are constant wheel loads from television camera mobile scaffolding going over the drain grates.
This causes the resultant bellying-out of the typically weak grating. This is made evident in the photo above. The groundskeeper of this field would be wise to replace these grates with an ADA cast iron grate or reinforced Perforated grating when they schedule the next maintenance on these drains.
Decorative Plaza Grates
The Founder’s plaza is a grand court at the business entrance and ticket booth at Arrowhead Stadium. Here, they have a fountain, an ornate hardscape, and memorial paver stone courtyard which requires quite a bit of drainage. Earlier in the year, I was called by an engineer from a local contracting company, George Shaw Construction, to discuss the replacement of grates that were failing at the Founder’s Plaza. At the time, the engineer was considering a stone based, reinforced polymer concrete grating called Jonite. This product proved to be too costly for the Chiefs organization, who decided to live with the broken grates – at least for the time being.
Upon arrival to the Founder’s Plaza, I quickly located the problem trench grating. I had seen this product earlier in the year in the general admission section of the adjoining baseball stadium, Kaufman Stadium. When I first viewed this grate, I suspected it was custom because I saw no markings. But here at Arrowhead Stadium, I was able to pick the grate up and view it in detail. The grate was an 8″ wide by 24” long galvanized cast iron product made by a boutique foundry out of California named Ironsmith. The grating pattern, Olympian (9045-8), is meant for pedestrian loads only.
After examination of a broken grate, it was clear to see the root of the failure. The recess of the trench which held the grate was designed to be one inch deep. The Ironsmith grate showed a one inch thickness, required to bring the grate flush with the adjacent hardscape. The grating design incorporated 1/4″ thick corner and edge pads (sometimes called pedestals) which are used to stabilize the grate within the track and prevent rocking. The actual rail body of the grate was only 3/4 inch thick. The grate cross bars, attached to the edge rails, are around 3/8” thick.
The pedestals are intended to be ground, if needed, to help facilitate stability. In this case, however, the pedestals acted as suspension points along the weakest axis of the grate. At first glance, one would think the strength of the grate would be a function of the multiple 1 inch thick cast iron support member spanning the 8″ dimension. In fact, the Ironsmith Olympian design is only as strong as the two 3/4″ edge rails that spans 12 inches between any two adjacent pedestals. This is a weak grate design and can be easily fail under light loads. No wonder so many of these grates were found broken.
Slot Drain Extensions
Elsewhere in this same plaza, other types of trench drains were used. Around the fountain, designers used a trench drain with a slot drain extension rather than a standard grate. These drain sections were 40 inches in length (one meter), typical of European style products such as MEA and ACO drain. Both of these manufacturers have a galvanized steel slot extension which is used in place of a grate. This allows the water to be drained into a 3/8” wide continuous slot that is well hidden from view. The slots are ADA compliant, as well, but watch out for cigarette butts clogging the slots!!! They only drain as well as they are cleaned.
One last example of trench drainage is along a sidewalk curb. This particular product is manufactured by ACO drain as shown by the brand mark. The grate, Type 494, is plastic and ADA compliant. It is resting in their K100S channel which is made of polymer concrete and utilizing a galvanized steel edging. This pre-sloped system is made in the European tradition and is pretty much identical to MEA’s Z1000 channel.
Arrowhead stadium displayed a nice assortment of trench drain products. At this venue, the exposed grating was heel-proof and ADA compliant due to the high volume of pedestrian traffic. Product manufacturers included Zurn, ACO, Ironsmith and possibly Polydrain. I was able to view design flaws of a product made by Ironsmith and see some significant deformation of grating that was under-rated for the application.
If you would like to discuss any of the above products, contact us at Trench Drain Systems (TDS). We specialize in all aspects of trench drains, channel drains and trench grating products. Call us (610-638-1221) for help with your project, or visit our website.