[JRTJH]

You're not going to get "one continuous awning surface" with three awnings installed along the side of your trailer. Look at your awnings and you'll see that there's a 9" to 12" gap between the awning side rails and the awning fabric. When you mount awnings "side by side" (or end to end) next to each other, the awning arms will "be as close as possible" leaving anywhere from 18" to 24" of "gap" between the fabric of the awnings. So, what you're going to wind up with is three "strips of awning with big gaps between them"...

I haven't seen any manufacturer come out with a "suitable way to create a single awning by closing those gaps"... When it rains, you're going to have at least two spots that people will be "jumping over to keep from getting wet" and either one or two spots where the "automatic rain dump feature" is going to keep the area under the awning "soaked"....

If what you're looking for is "more shade to cover the current gap" if you have a continuous awning rail, then you'll need to remove one of the existing awnings, install the "middle one" and then reinstall the awning you removed. That's the only way I know of to get the center awning fabric gimp (rope border) into the awning channel. If you have two awning rails, one for the front awning and a different one for the rear awning, then you'll need to install a third awning rail for the center awning. There may not be any aluminum backer plate to support the awning.

All that said, the FIRST step will be to measure the space (front and rear) where the slide flanges sit against the trailer side. If the existing awning side arms are mounted so that there is not enough room for the new awning side arms to be mounted without interfering with the slide movement, then I don't think installing a third awning is even possible.