I have struggled with where to locate our gray water tank while on the road. My first attempt was to strap it to the spare tire on the rear bumper of the pop-up camper, but that blocked the roof crank whenever I needed to access the inside. Next, I used straps to lash it under the front tongue area beneath the LP tanks. This was better but time consuming, especially at dump stations. It was also at the opposite end of the pop-up from the water connection.
I saw this design being offered on a Fleetwood/Coleman pop-up about 10 years prior to our model but could not find stock anywhere, including a query directly to the manufacturer (Barker). So, I made my own.
It is made of 2"x3/16" angle aluminum for the frame and 1"x3/16" flat bar aluminum for the cross support. I count 54 rivets used plus four bolts for the carrier frame and attachment to the pop-up's frame.
To use, I remove the two locking pins and let the carrier swing down, roll the tote off and into position under the pop-up. I just swing the carrier back up and replace the locking pins until I am ready to use it again. This was one of my most enjoyable modifications as it was easy to do, quick to show results and overcomes a major obstacle for myself.