Steel Vs Aluminium anchor

Porthandbuoy

Well-Known Member
Joined
27 Apr 2003
Messages
5,868
Location
The Gareloch
www.backbearing.com
At least one well known manufacturer makes similar sized anchors, one in steel, the other aluminium.
The advantages I see are:-
1) Lighter and easier to handle (handy if you've no windlass and a dodgy back).
2) Go the next size up for greater surface area in the mud.

So, anyone got an alloy anchor?
 
Yes. Got a Bulldog which is like a Fortress clone. Works well. Experience also of using a Fortress 37 on a 12 tonne boat - also works well.

Problem with both of these is stowage in the roller - same issue as with Rocna and Manson.
 
Ally Fortress anchors are great as kedges, in controlled situations and where you are not leaving them alone. Do not use them as main bower anchors. They set hard and fast but if the weather or tide turns, the weight of the boat comes on the stock, which is not strong enough to take the lateral load. I know of 3 Ally fortresses, which have been severely bent.
 
Ally Fortress anchors are great as kedges, in controlled situations and where you are not leaving them alone. Do not use them as main bower anchors. They set hard and fast but if the weather or tide turns, the weight of the boat comes on the stock, which is not strong enough to take the lateral load. I know of 3 Ally fortresses, which have been severely bent.

In addition to that, Fortress anchors don't reset well when the loading is low, they tend to skip across the surface instead. In light winds when the tide turns there is insufficient loading on the anchor and dragging can occur. This has happened to me twice in these conditions, even though the anchor was well reversed in initially.

I agree with most other posters, because the surface area is relatively high they hold extremely well once the load is applied. Therefore they make just about the perfect kedge.
 
Difficulty with setting a Fortress can be overcome in most sea bottoms by permanently installing the Mud Palms which we include inside of every box. The Mud Palms will lift the back end of the anchor up so that the flukes take a more aggressive angle into the sea bottom.

However, sea bottoms like grass, weeds, or rocks can be still be difficult for setting. The old adage that "there is no such thing as a perfect anchor" comes to mind here, and other anchor types might perform better in those bottom types.

Regarding a veering situation (reversing wind or tide), we contend that a well-buried Fortress anchor, with its massive surface area, is not more likely to break free than another anchor type in this situation.

That said, although the Fortress anchor is sharpened and tapered for deep penetration capability into a sea bottom, many sailboats simply do not have the engine power to "power set" and back down hard enough to deeply bury the larger Fortress, which will help insure that it will not break free in a veering situation.

This issue is obviously be more evident in a harder bottom type (hard clay), but less in a softer bottom (soft mud).

Safe anchoring,
Brian

Fortress Marine Anchors
 
I have used an aluminium Spade as a stern anchor for a number of years (in the Scandinavian context this is often the main anchor) and I have been quite happy with it.
Sets well, except on a very short scope, holds very well and easy to recover.
 
Aluminium Spade anchor

Our 25ft double Ender is at the change point for 2 sizes of Spade anchor. We went for an Ally version of the >25ft, and it has aprox the wt of the <25ft. Steel anchor.
We have had this for over 10 yrs, typically anchoring over 100 nights pa on the west coast of Scotland. We use 10m chain and 50m multiplat . The only time it has moved was when we picked up big patch of soggy carpet off the seabed!. We don't need to use the winch except sometimes when breaking out. We have been so pleased with our ally spade that we now have a small one as a kedge,- very handy and easy to use.
We got the spade I think in 2001 when PBO did the first of their recent series of anchor tests.
Malcolm
 
Regarding a veering situation (reversing wind or tide), we contend that a well-buried Fortress anchor, with its massive surface area, is not more likely to break free than another anchor type in this situation.



Fortress Marine Anchors

Interesting comment but on a pals boat with a Fortress 37 and a 12 tonne boat with an 80 hp engine, I have seen the Fortress anchor come up with the flukes jammed with clay and weed, needing to be cleared away before re bedding. This has been in areas with no veering issue but it makes you wonder what would happen if veering was required.
 
Fortress

We are 14m & 15 tons and I am using an FX 37 as my main anchor at the moment, sitting in a fast flowing tidal (the River Gambia) for the last month, no problem apart from the chain twisting up! Moved up river over the last few days, very soft mud so it holds far better than a heavy anchor (my Delta just poughs it it up!), biggest problem getting it back on board; normally have to drive it out.

Not sure what you are all about with it not re-setting/holding when the tide turns/wind shifts, I've never had a problem using mine and actually have more confidence in it than any plough anchor I've used. On saying that, I did need a slightly different anchoring technique to what I used to do, but they do what they say on the box.

I also use a small FX 11 as a kedge, and that has held me in 35kts+ on 10m of 10mm chain and 30m of 15mm warp (now upgrade to 50m of20mm) when the Delta dragged through mud, in a rather alarming squall that lasted about 30 mins.

Not connected to Fortress in any way, except as a very happy customer.
 
So it looks as though aluminium anchors are being used for both kedge and main, and some in quite demanding conditions too. I like the idea of being able to row off a nice light aluminium kedge though; much easier to handle than its steel equivalent I would think.

I suppose any anchor is capable of setting badly if the weed / mud / clay / whatever crud is down there is just wrong - - - and you're just unlucky. Unless it fails consistently that's no reason to condemn the marque (or your technique).
 
Top