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     Marc Hughston Moderator Username: hughston Post Number: 675 Registered: 03-2003 |
For MST 214A Fall, 2008 Anchoring Essentials. This attachment updates previous material posted here. Please follow the link below to download the materials on anchoring for the 2008 MST 214A class. We will use this in the Friday class, Oct. 10.
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| Marc Hughston Moderator Username: hughston Post Number: 611 Registered: 03-2003 |
Mark, thanks for your additions to the anchoring topic - I have incorporated them into an updated and downloadable document at the link below.
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| Mark Howe Moderator Username: unclemark Post Number: 324 Registered: 08-2003 |
These are my additions to the discussion. Hope none of you or yours had losses in the fires. See you Friday on the regular schedule. This will be the last Friday sail; daylight saving time ends next Sunday. Mark 1. Adequacy and condition of ground tackle. You must inspect and ensure the adequacy and condition of your ground tackle. In particular, check the shackle attaching the chain to the anchor, and the attachment point of chain to the nylon rode. Shackles should be zip-tied or wired so they can't unscrew themselves overnight. 2. Survey the anchorage. Take time to motor through and note how other boats lie, the depth and slope of the anchorage, and the location of rocks or other dangers you need to keep clear of. This is so important. I also add the idea of chatting with other skippers already anchored. By opening up a friendly dialog, you may get some very valuable advice about that rock or wind hazards during the night. 4. Use appropriate scope. This is the ratio of rode length to water depth. In general, 3:1 for a lunch hook, 5:1 overnight, and 7:1 or more for strong conditions. Add your freeboard (height of bow roller) to depth for the calculation. You will see much greater scopes listed in books from the East Coast. They traditionally use much less chain than we do [maybe 6']. There is a major discussion on this site for scope necessary for all chain vs rope. Steps for setting with a single hook. 1. Survey 2. Hang down on the bow, [Be sure your crew understands what this means and be careful not to chip the gel-coat.] lower away when the boat is stopped 3. Back down and pay out rode for desired scope 4. Set the anchor Steps for setting bow and stern. 1. Survey 2. Lower the stern anchor first (this is usually the easiest procedure) There are pros and cons to this which will require further discussion. Most commonly the bow is lowered first because it is to weather. There are at least 2 major concerns when lowering the stern first and 1 big advantage. 3. Set the stern after paying out rode with at least 3:1 scope 3. Hang down on the bow, lower away when the boat is stopped 4. Back down and pay out rode on the bow, haul in on the stern until desired scope is achieved 5. Set the bow anchor | ||||
| Marc Hughston Moderator Username: hughston Post Number: 609 Registered: 03-2003 |
Here are some thoughts on anchoring. Please review this with your anchoring experience last week in mind. We were going to review this in the class on Friday the 26th, and since it has been cancelled, I have posted it below. For a one page summary of the golden rules of anchoring as they apply to our class, click below to download the MS Word document.
******* Volumes of material have been written on anchoring and the purpose of this class is to introduce you to the basic concepts and practices. Please post questions or discussion items within this topic. Colgate's "Colgate on Cruising," one of your texts, has a decent surface treatment of the subject beginning on page 61. For a complete treatment on anchoring in 300+ pages, get "The Complete Book of Anchoring and Mooring" by Earl Hinz. That should make for some nice bedtime reading. It's really good. ******* Text of the golden rules of anchoring, same stuff in the downloadable document above, is pasted below. On Anchoring Saddleback College MST 214A Marc Hughston Experts report that more boats are lost each year to anchoring problems than to storms and heavy weather. The Big Picture: Golden Rules of Anchoring 1. Adequacy and condition of ground tackle. You must inspect and ensure the adequacy and condition of your ground tackle. In particular, check the shackle attaching the chain to the anchor, and the attachment point of chain to the nylon rode. 2. Survey the anchorage. Take time to motor through and note how other boats lie, the depth and slope of the anchorage, and the location of rocks or other dangers you need to keep clear of. 3. Adjust your methods to the situation. Others before you may dictate whether you anchor on a single hook or bow and stern. Power boats swing more to the wind, and sailboats more to the current. All chain rodes result in a smaller watch circle. If there is a conflict with the swinging circle of another boat, the last boat in must be the first one to move. 4. Use appropriate scope. This is the ratio of rode length to water depth. In general, 3:1 for a lunch hook, 5:1 overnight, and 7:1 or more for strong conditions. Add your freeboard (height of bow roller) to depth for the calculation. 5. Set the anchor. Set the anchor. Set the anchor. With all your anchor rode out, gently ramp up to cruising rpm (increasing gradually over 20-30 seconds), hold at cruising rpm, and sight across a range to see if you are dragging. Placing your hand on the anchor rode leading out will enable you to feel when there is tension, or if the anchor is skipping along the bottom. Steps for setting with a single hook. 1. Survey 2. Hang down on the bow, lower away when the boat is stopped 3. Back down and pay out rode for desired scope 4. Set the anchor Steps for setting bow and stern. 1. Survey 2. Lower the stern anchor first (this is usually the easiest procedure) 3. Set the stern after paying out rode with at least 3:1 scope 3. Hang down on the bow, lower away when the boat is stopped 4. Back down and pay out rode on the bow, haul in on the stern until desired scope is achieved 5. Set the bow anchor Caution: Lower the anchor, don’t drop it Avoid piling the chain up on top of the anchor that is on the bottom Pay out the rode in as straight a line as possible Extra: Think about the pros and cons of tying off the bitter end of your anchor rode, or even having it shackled straight to a strong attachment point on the hull. How do you keep from losing the whole rig overboard? How do disconnect everything in a big hurry to get out when a Santa Ana or Westerly Gale sets in? Under what conditions is chafe on the nylon rode a problem? How do you minimize and manage it? | ||||
| Mark Howe Moderator Username: unclemark Post Number: 615 Registered: 08-2003 |
Just to review last Friday. These were demonstrations of all the things that can go wrong; next week is the practice. Review the anchoring page in your handouts pg. 15. I wish I knew why it takes so long to get the boats to the class area. Sometimes I feel like I am herding cats. 1st demonstration was putting out a bow anchor; you learned how hard it is to position the bow precisely where you want to drop the anchor. Then drop it while trying to feel it hit the bottom and at the same time, keep the boat moving backwards so you don't foul it with the chain. Next you learned how hard it is to back a boat straight while paying out the bow rode.. I say keep a little bit of tension on the rode so you can feel if it starts to dig in, but not enough so that you interfere with the backing. But you can assist in steering with an occasional tug on the rode to pull the bow back into line. 2nd demonstration was putting down the stern anchor. Continuing backwards with a precise location in mind, dropping the stern anchor while moving the boat forward until approximately in the middle between the 2 anchors. I always forget to emphasize you don't want to put the anchor under the pulpit because it destroys the railing of the boat. I recommend bracing yourself against the pulpit for balance and then lowering the chain directly out of its locker into the water over the pulpit. At one point one boat had it tied off over the top of the pulpit; this of course can destroy the pulpit which costs about $1000. Even if you have a snarl in the line, letting the snarl go overboard while you tie it under the pulpit is worth the extra few minutes it takes to get back to the snarl. Then running it to the winch and pulling tension [with only 1 or 2 wraps and no cranking necessary]. 3rd demonstration was doing the identical thing except putting the stern anchor down 1st. This has the obvious advantage of not having to do any backing. You drop the stern, drive the boat directly to where you want the bow, and then use the stern rode to pull yourself back to the middle. 4th demo was two anchors on the bow so the boat can pivot into the wind, but we ran out of time. [Ref: herding cats.] Ideally in the demonstration we would have had all 4 boats lined up side-by-side. For one brief moment I think we did a pretty good job of having 3 lined up. Several times I found myself repeating myself "don't tie it off". If you tie it off, you have no flexibility for feeling the 'nibbles' as the hook is set, and you defeat whoever is attempting to steer the boat backwards [or forwards]. To assist steering you just hold tension briefly, just long enough to get the bow swinging the other direction. This requires a number of times doing it before it begins to feel comfortable. These posts will be transferred to the anchoring section Marc started. | ||||
| Kathleen C. Matlock Member Username: kcmatlock Post Number: 10 Registered: 01-2008 |
In preparation for Friday night's anchoring practice, I uploaded my cheat sheets that I use while cruising. I have my entire crew review them prior to arriving at our anchoring spot so that we're ready when we get there.
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on anchoring
On Anchoring - revised