Feedback Wanted: Two-Leaf Gate Design for Allerton Abbey

To Sum It Up:
Paul and I put our heads together and came up with a design we could both settle on for half of the front gate at Allerton Abbey. Please review and post comments and questions here.

More Details:
We're nearing completion of the fence repairs over at Allerton Abbey, and to complete the fencing project we want to install a gate in the front driveway. A few guidelines for us as we designed this:
- as close to purewood as possible (zero metal fasteners)
- 14' wide opening and no lintel, to facilitate large vehicles like excavators and stuff
- protects the inside from deer predation, and contains chickens

There will be two leaves (AKA doors) at this front gate, and they'll be secured together when the gate is closed. The gate will open only one-way, so the counterweight shown in the diagram won't interfere with the height of the fence. Those of you who have seen the front gate of the Lab will understand our gate - counterweight mechanism here.

I'm hoping natural builders can have a look at the images below, and provide any feedback, pointers, obvious design flaws, questions, etc. in an effort to make this design better. At this point, only the vertical support post is installed. Please post your responses in this thread. Thanks!

Here's an image I sketched together to start the ball rolling and communicate with the rest of the Boot Team:



This is the gate design, with the junkpoles removed from the gate leaf/door. It's kinda "busy" otherwise.



Some details on the measurements of the different pieces of roundwood are included here (imperial measurements, sorry for you metric folks out there...!):



Some additional details on how the vertical leaf posts are secured to the main gate bar at the top. Being purewood as much as possible, we're hoping to use mortise and tenon, with an extra helping of drawbore securement in the form of hardwood dowels plunging through the two joined pieces of wood.



That's all for now. Please post in this thread any questions, guidance, feedback, and so on you may have. I can clarify the design should you have any questions.

Thanks...!!!

Hi Stephen, here are some thoughts....

1. Is there a person door very near by?  Opening that to get a human through might be a bit much.
2. A consideration might be to make the leaves different widths.  One narrow one for humans and a wide one for cars.  Open them both for bigger equipment.
3. It's very hard to make a gate that fits tight to the ground (no lintel) that can swing without interfering with the ground (or snow/ice).  Unless it's opening downhill.  Hopefully that's the plan here.
4. A nice feature of the main lab gate is that you can lift or push down on it as needed.  The rebar pivot you show would prevent that.  I'm not sure how the main gate pivot works but putting this gate on a sphere shaped pivot might allow for some up and down movement on the gate as it opens to work around terrain or snow.
5. Make sure you think about how to get thru the gate after a snow storm. Keeping the counterweight above snow may be a terrific idea.
6. Consider a tight junk pole down low for chickens and a loose one up higher so that you can see through the gate a bit. Residents might want to see an approaching vehicle sooner and visitors might like to see in a bit to make sure they're at the right place.
7. It might bump/slide/scrape across the ground easier if the lower cross brace was the bottom most part of the door. If random junkpoles are snagging on rocks, they could break be annoying.
8. A long counterbalance (like on the front gate) might be easier to fine tune than the style shown.  If there's room for it to swing...
9. You may want the counterbalance to be adjustable so if you change things, it can change with them.
10. Be sure to pin the tenons on the cross braces too so that they don't pull out of the vertical logs.
  10a. "Drawbore" clarification:  I believe a draw bore is when the pin holes deliberately don't align and as you pound the pin it, it draws the tenon tighter into the mortise.  Otherwise I think it's just a pinned tenon or something like that.  
11. If you want to bump up your joinery work, I think rectangular tenons in rectangular mortises would be much stronger and keep the door from twisting.  Basically take the top end of your 7" support posts and turn them into 2" by 7" rectangles (8.5" long per your drawing).  Chisel a rectangle in the gate bar for it to slide up into and pin it.  It will require more precision with the chisel work but the door won't twist nearly as much if you get it right.  Same for the horizontals (1.5" by 4.5" tenons however long you think is good)

Mike Haasl wrote:

3. It's very hard to make a gate that fits tight to the ground (no lintel) that can swing without interfering with the ground (or snow/ice).  Unless it's opening downhill.  Hopefully that's the plan here.

Yes! I don't know what the topography is, but have you considered a "portable lintel"? Something that's very easy to move? Maybe even like a ground level bar like you have to raise to get out of some parking lots?

A gate I made was slid over a piece of rebar so I could lift it to swing it, but it was very light. It was on grass, and in a bit of an awkward spot for mowing, which would have a similar effect as snow fall. A separate "people gate" which has a step-over height above most expected snow fall heights, might be indicated.

The center bar holding the junk poles could be diagonal to work against the  the potential sag.