In reply to martinturner:
One of my "grand plans" is to write a comprehensive instructional text on scrambling and mountaineering ropework as one doesn't really currently exist. So, I'm not surprised at all your questions...
The first point to make is that most scrambling and mountaineering "ropework" is currently taught within the context that the you have an "instructor/guide" and a "client/novice" rather than two equals. As such there is a slight bias to making things super safe for the second and the leader doing all the ropework. In real life, scrambling as equals you are much more likely to do things like un-rope completely on easy ground and not be as pedantic about always being connected to belay anchors.
As regards "belaying" when scrambling, you have a limited but still quite varied array of options:
1. Tight rope, braced stance
2. Direct Belay
3. Body belay (braced position, no anchor).
4. Body belay, with backup anchor
5. Italian hitch, single anchor
6. Italian hitch, equalised anchors
7. Belay plate, semi-indirect to anchor/s (as per normal climbing)
These options obviously vary both in terms of speed and security. It is probably stating the obvious, but:
Option 1 isn't very secure and is only ever suitable for VERY short sections.
The preferred options for speed are often 2 and 5 but they require BOMBER spikes or gear.
The next best secure options are option 6 (with well positioned anchors) or 7.
The use of body belays (options 2 or 3) is generally avoided but they may well be the best option with poor or non-existent anchors.
In some circumstances (e.g. on large ledges) you will decide NOT make yourself safe, in others you will definitely want to. A similar decision also needs to be made as regards the second. These decisions obviously influence which belay options are appropriate.
In some circumstances the 'pitch' may be literally 3 metres, in others it could be 50+ metres. Generally the longer the pitch the 'more secure' the belay needs to be. Again this will determine which options are sensible.
So, coming back to your original questions:
The whole premise for your first question is slightly misplaced. As mentioned above, the overriding process is to consider:
- How secure a belay do I need to provide?
- What spikes, boulders or other gear are available?
- Do I want to make myself safe?
- Do I want to make my second safe on arrival?
So assuming that you do want to make yourself safe, there is ONLY one sensible way to do it which is to connect yourself securely and with no slack to the anchor/s with a DYNAMIC element within the attachment. The most common method is exactly the one you describe - clove hitch on the nice stretchy rope you are already tied to. Missing out the rope and for instance, clipping a sling around a spike direct to your harness is a really, really shit idea. In the event of any shock loading there's no stretchy rope or tie-in knots to reduce the forces involved. I personally cut a dyneema sling 2/3 of the way through doing this on a route in Alps in 2010 and I certainly won't be doing it again!!!
See
http://dmmclimbing.com/knowledge/how-to-break-nylon-dyneema-slings/ for more examples of what could happen when you only use slings and not the rope.
As to your second question, people generally use an Italian hitch because it's quicker. This is most often true when there is a big solid spike and especially if you decide that you don't need to make yourself safe first.
However, most people still carry a belay device because with situations requiring multiple anchors or where the anchors are positioned low down, a standard semi-indirect climbing belay is the better approach.
Finally, as others have already pointed out, it is worth noting that useful scrambling ropework for grade 2/3s and ML ropework are almost mutually exclusive. The security on steep ground ropework in the Summer ML syllabus is intrinsically limited, with the focus being on using the rope alone. The specific skills of using direct belays and body belays are transferable, but that's about all.
HTH
Post edited at 19:00