Tray design- coaming rail pros / cons?

[POD]

Going to be building a tray to replace the big box on the rear of my 130. One of the questions I'm considering is whether to have a coaming (i.e. raised rail around the perimeter of the tray) or have the top flat to the edge.
What are the advantages & disadvantages of each design? I can see that if you are grabbing something heavy and sliding it off the edge, the coaming would be a mild annoyance, but when is it an advantage? Other thoughts on this?

[vnx205]

It would stiffen the tray. I suppose you could get the same rigidity by having the lip go down instead of up.

[POD]

No difference to rigidity- it will have the same material for the frame either way, it's just a matter of how the members intersect to get the top flush or recessed.

[steveG]

The tray on my 130 single cab has the side rail raised about 10mm above the timber decking. The RHS side rails are 40mm (possibly 50) wide. The radius on the RHS means its not a full 10mm vertical flat face on the rail - probably only about 5mm.
No issue lifting things off, but its enough of a lip to be a positive stop for something that is tied down when the sides aren't fitted. When the sides ARE fitted, there's not much of the horizontal rail surface exposed anyway as the side piece covers most of it.
Our slide on camper locates snugly inside the rail, so it provides a bit of lateral location for the camper in addition to the tiedowns etc.

SIL's alloy tray on his work Hilux has about a 25mm lip, and I reckon its a pain. Whereas on mine to lift something off is generally a case of lifting a corner slightly until it gets onto the rail, on his its a definite lift, and his rail is also just the edge of an extrusion so quite narrow. Narrow enough that it almost bites into the thin rails on the bottom of plastic tubs etc, where as on mine with the wider RHS once you get something on the steel its easy to then slide it off.

Although mine goes all the way around the sides and rear, I definitely can't think of a good reason to have it at the rear.
With the height of a Defender tray - I highly recommend having a step at the front of the tray. Mine is just a U shaped loop of the tiedown rail pipe. Makes getting yourself on/off the tray easy and safe. Good grip on the headboard tube, foot on the step and you're good. No chance of slipping off the side of a tyre or wheel hub climbing up, or jarring your back jumping back down.

Pulling out my soapbox - why don't tray makers use different length pins on the hinges for the removable sides? I know the standard answer will be "its easier and cheaper to make if they are all the same length" - but really?
On my 130 tray, there are 3 hinges on the side panels (2 on the rear one). Try to line up 3 hinges on a 2.7m side panel that isn't 100% straight when the hinge pins are all the same length and therefore need to engage at exactly the same time!!
Making the 3 pins slightly different lengths even by 2 or 3mm would make it sooo simple to engage one at a time.
Stepping off the soapbox again...

Steve

[Tote]

Mine has a coaming on the sides but none on the rear. To be honest I have never noticed a disadvantage but it does make locating the slide on pod easier, loading pallets isn't an issue from either the side or back and the coaming gives a purchase point to lash a solid load against to stop it sliding. There are a few tray build threads on here and the body builder manual is in the files section of the site, both are good sources of info, the golden rule is anchor the tray at the back and make the front mounts flexible enough to prevent chassis/mount cracking during articulation.

Regards,
Tote

[MLD]

i can't offer a comparison. i have a tray where the deck is level (about 2mm lower) from the coaming. I use rubber mat that is about 10mm thick (big green shed offering), which results in the upper surface of the mat being higher than the coaming. I've not had any loads fall off the side except 1. that being the dog who want to wanted a better look mid corner and exited stage left. he had a long happy life afterwards.

I've been wanting to retire my tray for a while and the next tray will be set up similar. i'll set the coaming height about the same as the mat depth. I run 35s on neg 25 rims and need a tray no narrower than 1880 and ideally 1900 wide to cover the tyres. I have a generic 1780mm wide canopy and i find the 2" flat surface on outside of the canopy body is enough for a toe hold when i'm struggling to pack the fox wing away. at 1900 it offers a tad more toe.

if you don't have it, the LR specs for the tray install.

[oldie]

Hi, I have a MY2010 110 single cab chas which I bought new with a Top Dek steel tray already fitted. There is no raised edge to the tray and I find it a very good solution for my uses. About 5 years ago I had it hot dip galvanised.

I use the "truck" for all sorts of dad jobs - moving furniture, soil and gravel pick up, and most importantly to carry our Trayon slide on. For the Trayon, I bolt a couple of pieces of 25 mm square tube along the outside of the tray for a bit of peace of mind.

I suspect the tray is a bit too rigid as 2 of the 6 chassis mounting points have broken. Probably not surprising given we have done 100,000 km of outback tracks with the Trayon on.

And yes, the 3 hinge points is a challenge but easily fixed by taking an angle grinder to the pins.

Keith
Oldie

[W&KO]

Pulling out my soapbox - why don't tray makers use different length pins on the hinges for the removable sides? I know the standard answer will be "its easier and cheaper to make if they are all the same length" - but really?
On my 130 tray, there are 3 hinges on the side panels (2 on the rear one). Try to line up 3 hinges on a 2.7m side panel that isn't 100% straight when the hinge pins are all the same length and therefore need to engage at exactly the same time!!
Making the 3 pins slightly different lengths even by 2 or 3mm would make it sooo simple to engage one at a time.
Stepping off the soapbox again...

Steve

100% agree, it must even be a pain when they test fit and final fit during manufacture [emoji2369]

We used to trim the pins on the work truck and utes post delivery……

[MLD]

I suspect the tray is a bit too rigid as 2 of the 6 chassis mounting points have broken. Probably not surprising given we have done 100,000 km of outback tracks with the Trayon on.

Keith
Oldie

assuming i interpret your post correct - have a read of page 12 & 13 of the attached document in my earlier post. the tray is fixed on the rear cross member and on the front mounts only. the middle mounts are not fixed and the tray only rests on them with a rubber buffer.

[JDNSW]

I had a trayback 2a many years ago with a two inch raised coaming all the way round. It was a pain, especially for sweeping or hosing the tray, so at a minimum I would have no coaming at the rear.

While I do not currently have a ute with a tray, I do have a tandem trailer with a flatbed tray. It has the coaming only about 8mm high on three sides, formed by the stiffening angle pointing down. I find this is quite satisfactory - enough of a lip to stop things sliding off when loading with the sides down, but not enough to be a problem otherwise. And I also support the idea of different length pins on the hinges, especially since the trailer is 3m long!

[towe0609]

My 300tdi has coaming on the sides but not rear.

The Td5 is flat - buts got the canopy permanently mounted to I've not really had the opportunity to 'experience' it ie. I can't really compare.

The downside for me is that the canopy for the 300tdi is as wide as the tray and so has to sit on top of the raised edges, rather than within, and there is far less surface tension for the box and nothing holding it in. As I use over centre fasteners to hold it down (I know, I know) ... this matters. I have reasonable tension vertically, but its wildly insufficient horizontally - not helped by the large load being spread on a relatively small surface. Not good for wide loads.

When the canopy is off, I find having the stop for things being tied down very helpful. Its never really been an issue, but could always slide something off the back if it becomes tricky to lift over the edge.