DUCTBOY:
Greetings everyone,This is my first post so bare with me.Iam going to futher my training into tec diving and want to start buying my equipment in order to get use to it.My first question is I want to buy the BP/W doubles from DSS but also want to use the set up for singles in order to dive with my wife.They told me I would have to order the LCD 30 & LCD 50.Why cant I use the 50 for both single and doubles.Thank You.
Hi Ductboy,
Single wings and Doubles wings differ in more than just lift capacity. Single wings and Doubles wings are shaped differently.
Keep in mind the assembly order is diver, backplate, wing, tank(s) This means the wing is samwiched between the backplate and tank(s)
Wings are called "wings" because they all wrap up around the tank or tanks. Consider a horizontal diver, with just a bit of gas in his wing. This gas will rise to the highest point in the wing and form two bubbles running along each side of the tank. All wings have a center panel that does not inflate surrounded by a horseshoe, or in some cases a donut shaped area that does inflate.
Backplates are not flat, and a single tank contacts the backplate only on the narrow raised center section of the plate. That means the center panel of a singles wing can be quite narrow, maybe only a few inches wide. Keeping the center panel narrow prevents the wing from wrapping to a point at or above the top of the tank. If a wing is allowed to wrap well above the tank it can make venting the wing more difficult. All wings wrap, but limiting wrap improves performance and ease of use.
The center panel on a doubles wing needs to be a little wider than the center to center distance between the two tanks. This distance is set by manifold and bands that join the two tanks. Double tanks contact the backplate down each side of the plate, not on the raised center channel. Most double tanks are about 8 1/2" apart. That means the center panel of doubles wings needs to be ~8 3/4" wide. This is far wider than the 3-4 inches possible on singles wing.
What happens if you use a doubles wing with a single tank? Not only do you have a much larger wing than necessary, you also have a much wider wing. A doubles wing will wrap a single cylinder so far that the "two gas bubbles" along each side of the tank will be far above the top of the cylinder. To vent such a "tacoed" wing the diver is required to break horizontal trim and be near vertical in the water. In addition using a doubles wing on a single tank will creat a lot more drag from the floppy oversized wing. That defeats one of the main benefits of a BP&W, less drag.
What happens if you use double tanks with a single wing? The doubles are ~8 1/2" wide where they contact the plate, but the center panel of the singles wing is far smaller. A good percentage of the inflateable portion of the singles wing will be trapped between the tanks and the backplate. Reduced wing capacity as you add an second tank is not what you want either.
My suggestion would be to buy a BP&W with a single tank wing, and wait to get the doubles wing. There are many doubles wing to choose from. Which one is correct for your application depends on the tanks you will be using, and what exposure suit your will be using, and to some extent where you will be diving. If you don't know now what tanks you might use in the future, or what exposure suit you might need for the longer exposures doubles typically bring you'd be hard pressed to make pick the best doubles wing.
Let me know if you have other questions.
Good luck,
Tobin
