Morgan 27 Modification and Tuning
I'm not exactly sure where this is originally from, I found a typed paper copy and think it is interesting. From the sound of it, it must have been written in the 70's. The author is Tony Johnson, President of Competition Sails, anyone know Tony or heard of Competition Sails? -Chris
The Morgan 27 is a design, like all good designs, that has withstood the test of time. The fact that is is still competitive today is a real tribute to its designers, Bob Bienvenue, Bill Libie, and Bob Dotson. There are some modifications that have proven helpful in making this boat perform even better and we'll discuss them in this article. The main point is under most rating rules, with somewhat inexpensive modifications, a Morgan 27 can even be a more highly competitive boat.
The Rig
One of the most immediate modifications necessary is the anchoring in of the upper shrouds into the hull or a bulkhead. The upper shrouds can actually lift the deck slightly if this isn't done and this presents on serious problem: it allows the section of the mast from the spreaders up for fall out of column to leeward. This in turn distorts the mail and allows its leach to fall too far off the leeward. It also causes the upper section of the genoa to fall off the leeward and headstay tension is lost. The harder it blows, the more these problems occur, having an adverse "snowballing" effect. It is advisable to install 1/4 x 19 stainless steel shrouds after the uppers are securely anchored. (Standard shrouds are 3/16 inch) The upper shrouds need to be heavily tensioned. Ideally in 12-15 knot true winds with full sail on the wind, the mast should be straight laterally. A very slight bowing off the leeward in these conditions is preferable to a hook to windward. Fore and aft, the mast should have a very slight, even bow forward at the spreaders. This means that the forward lowers are carried tighter that the aft lowers. The aft lowers should be just tight enough to avoid "pumping" to windward in a chop. Backstay tension affects the headstay tension, so a 10 foot bridle backstay adjuster or hydraulic adjuster is helpful. Carry tension as loose as possible to keep the headstay from bouncing in a chop. Consequently, the harder it blows, the harder you tension the backstay to windward. Mast rake should be determined by your helm. A 4 to 6 inch rake after is preferred if this balances your boat to windward in the 8 to 12 knot range. It is advisable to change to 1/4-1 x 19 wire in the headstay and 7/32 inch on the backstay. Old shrouds (3/16 inch) can by used to make the backstay bridle. Remember with larger rigging, the cotter pins are larger and all tangs need to be redrilled, no easy job at the masthead!
The Keel
The Morgan 27 has a highly swept bulb type keel. This keel is not highly effective by today's standards, but on a narrow beam water line, the large concentration of lead at the bottom provides stability that the hull form doesn't. It also allows the draft to be less which is helpful under most rating rules and when you're pushing off a shoal. The large amount of keel sweep puts a great deal of stress on the hull where they join and particularly at the leading upper edge. Make sure that your keel is tightly pulled up and bedded against the hull. An extra bolt in the forward part of the keel will eliminate its tendency to separate from the hull there.
The Morgan 27 has a strong tendency to round out to weather, or broach, in heavy air reaching and even to windward. This is attributed to a variety of factors which we won't go into detail on, however, there is a simple way to eliminate this tendency and increase all around performance. Fill in the area from the aft lower tip of the keel to a point 1-1/2 inches from the aft upper edge of the keel. This are can be filled with a piece of plywood or aluminum and easily micro ballooned, or puttied for fine fairing. While the boat is out of the water, also refair all the hollows and rough spots out of the keel. Try to place the maximum keel thickness approximately 35% aft. This fore and aft placement is found by taking the length of the keel at the top (after filling in the trailing edge) and finding a point 35% of its total length aft. Do the same at the bottom and draw a straight line between these two points.While refairing, try to achieve a smooth tear drop shape.
One of the most important things to reshape is the leading edge and particularly the forward 1/3rd. The Morgan 27 keel is thicker at the bottom than the top. But a progressive parabolic shape (even "U" shape) is not maintained. The upper forward edge almost comes to a point. It is very important to make the leading edge parabolic, even though this parabolic shape is progressively narrower toward the top. This general refairing will result in better lift. The filling in of the area aft reduces side slip, adds greatly to the directional stability (tracking), and greatly enhances rudder control. This top of keel modification is not too time consuming and is relatively inexpensive compared to a new keel.
Naturally a new keel of increased draft, improved shape, and approximately the same weight would be ideal. A 1/2 tonner's or a partially poured 3/4 tonner's keel might be available and your old keel's lead could be melted and used. This would be a more expensive alternative.
Sails and Rating
The keel modification we discussed does require a larger mail with a center of effort slightly farther aft. The added keel area aft tends to induce a slight lee helm in light air. This is actually a good position to be in because almost all rating rules are very lenient on mainsail area. The new MORC 3D rule allows an approximate 10% larger main without an more rated mainsail penalty than before. The foremost advantage with the larger main is that the area needs to be added to the foot. This: 1) greatly reduces the aspect ratio penalty, 2) adds area aft where it isn't stalled by the mast and less backwinded by the large overlapping headsails, 3) gives you a longer boom to better project "surfers", "bloopers", etc... and 4) allows you longer battens and headboard which enables the sailmaker to proportionately build more free roach into the leach.
It is very important to work with a sailmaker that has had a lot of first hand Morgan 27 experience or one that is close at hand because your rig and keel modifications greatly affect the sailmaker's sail modifications.
When measuring be sure to eliminate as much weight aft as possible, as this weight aft increases waterline quickly. Give thought to moving your aft winches to the cabin top. This removes weight aft and places it forward. More importantly, it eliminates at least one crew from an already small and overcrowded cockpit. Batteries and other heavy gear should also be relocated forward. MORC's new rule now increases prop factors approximately 40%, so a small inboard, forward, might be another consideration.
A new boat might not be in your already overstretched boat budget, so before you scrap your old one, think modification. All the changes we've discussed not only make the boat more competitive, but also make it easier to sail and sell later.
-Tony Johnson, President, Competition Sails
How to trim the sails on a Morgan 27
This was sent to me via email back in 1999, from Del Gould (M27 Nautilady). My brother found a paper copy that I printed, so I've retyped it here from everyone to read. Thanks Del! -Chris
Here are a few tips worked out during our M27's racing career. Won the fleet championships the first two years in the early 70's. While we don't have the best sails now, having blown out everything that was original, we've done quite a bit of fast cruising since. Put on a roller reef jib and full batten main in order to sail short handed. Do miss the 170 though, it was clearly the best sail for the boat, but costly for a decent one.
Light Air: 0-7 knots
Smooth water:
Main:
Genoa (170):
Crew:
Reasons:
Choppy water - same as above except:
Moderate Air: 7-14 knots
Smooth water:
Main:
Genoa:
Crew:
Reasons:
Choppy water - same as above except:
Reasons:
Heavy Air: 12-18 knots
Main:
Genoa (150):
Genoa (135) - same as above except:
Downwind with Chute:
Always tack zig/zag course 15-20 degrees off downwind at all winds capable of flying chute. Never set course straight downwind with chute because slowest speed due to no lift developed by chute. Always tack same when flying jib in higher winds. Reason - increased boat speed more than makes up for additional distance traveled in zig/zag path.
Use caribiners to tie chute lines to outer shrouds to prevent chute oscillation and potential broach if heavy aft waves. Never let stern move laterally when lifted by rear approaching waves.
Conclusion:
Hope these settings help you as much as they worked for us. Our M27 was built in 1972 with the cruising interior and outboard power. Our jib sheet winches are mounted on either side of the cockpit ahead of the chute winches. Only the halyard winches are mounted on the cabin roof on either side of the hatch, using sheet stoppers. Tracking downwind, especially with the chute, is essential for this boat. One race was an all downwind 12 hour race, including a downwind chute start (scary) and unexpected 180 degree windshift at the farthest mark. Hosed 300 boats in all classes. Finally caught at finish line by half dozen maxi's and ex-America cuppers in virtually no wind conditions (Having tall mast has advantages).
Good wind and happy sailing, Del Gould (Nautilady)
copyright© 2008 CMJ