UKC

I'm going to climb buccaneer at boulder ruckle. A fall from the top crack will definately land me in outer space without enough rope to descend. So I was wondering about having my Alpine up rigged with the lead rope locked and a small loop ready to pay out when I start the ascent of the twin ropes back up to the crack. Having this all rigged before I leave the floor would make the start of the rope ascending a lot easier. But will my Alpine up explode if I fall with it already rigged? I'm guessing not as the rope stretch will protect it. Any advice against doing this?

I doubt your alpine up would explode, as the force of you falling on it wouldn't be higher than a factor 2 fall which it's designed to withstand. But having never done what you've suggested I can't be sure.

But my main thought is why pre rig it? I've used the AlpineUp a lot and whilst it is my go to device for everything I do, even I have to admit it's not the smallest thing. Not sure I would want something that size and metal attached to my belay loop whilst on a hard lead I think I might come off.

Depending on the rope diameter, size of the fall, amount of wear on your device, orientation of the device during the fall, I wouldn't be too suprised if the AlpineUp slipped a small amount even pre locked. This potentially would mean the AlpineUp would hit your knots and make it so you can't get slack through. To mitigate this you could leave a larger loop of rope out of the device. But now you have to think about maybe you'll try and clip the loop by accident when stressed, or it gets caught on something and probably a hundred other things!

So any advice against doing this? Not really. If you think it will make your life a lot easier then I wouldn't expect it to be dangerous. Maybe try this set up taking a lead fall at a wall, even if it does explode you're still tied in.

Would I do it? Probably not. I would be hanging in space put a prussick on the rope above me, stick a sling it for a foot loop and stand up to thread the AlpineUp. Then ascend by standing up in foot loop, pull slack through locked AlpineUp, sit down on AlpineUp, slide prussick up the rope and repeat.

The alpine up is my go to belay device, but I don't tend to use it for ascending because if you put the dead rope through a pulley above to create a 3/1 it reorients the device so it doesn't lock.

The worry isn't that the Alpine Up will explode, it is that it might damage the sheath.  Jim Titt found sheath damage in some severe tests of the Alpine Up; I don't remember specifics.  Seems better to me to have an autoblock and foot loop installed (as is often done for glacier travel) and then after a move up, install the Alpine Up on the harness as a progress capture device.

If you want to have the Alpine Up installed and ready to go, perhaps the best idea would be to isolate it from the load of a climbing fall by clipping the climbing rope above the Up back to the harness with a Munter Mule, leaving the Alpine Up dangling on a small loop of slack.  Fall loads would go straight to the harness via the Munter Mule, but once hanging one could undo the mule and lower onto the Up. 

Obviously, this is something that should be practiced in the gym or hanging from a low tree branch before trying it in the field. Getting the Munter out of the system after transferring to the Up is a potential issue.  In this regard, note that a loaded Munter can be "popped" off the rope.

You are overthinking this a little but that's understandable if it's close to your limit. Prusik loops are fine for 10-15' if you end up hanging below the overhang. The kit and knowledge to ascend a rope should be standard for anyone climbing here for obvious reasons but you don't need to do anything special for Buccaneer. I wouldn't pre-install anything on your lead rope as this just seems like adding more unnecessary complexity. Perhaps it's also psychologically preparing you to fail rather than succeed. 

Beta: ​​​​​​it's typical Ruckle: steep, intimidating but steady if you can jam and don't hang around for too long. A failure in the top crack will most likely involve a slump onto one of the many pieces of gear you have laced it with. Great route.

Thank you all for the advice. I'll be prepared with a couple of prussics and will practice with the Alpine up at the wall. 

One or two ropes?

Two

Consider taking a Petzl micro traxion & a tibloc. You can ascend a full pitch easily with those either with a sling foot loop or as a 3:1 z rig and your hands.

Ascend the rope clipped to the highest gear. Your belayer can belay you on the other rope if gear fails etc. 

You can also use a micro traxion to protect a lower off from bad gear. Not obvious but quite clever.