Avon SeaRider A Frame Attack

Tomas · 21 October 2006, 17:18

I took delivery of a 4.7m Searider in Anapolis in the states in 1998. I ordered the SeaRider for trans-shipment to the Virgin Islands with the understanding that HEAVY DUTY was the name of the game. I cleared the boat out of the customs warehouse and trucked it to Virginia where I did some initial assembly, Jockey Console, Outboard, Controls and placed it on a trailer bound for Miami. It wasn't until it arrived down here that I went to install the A Frame. Given the substantial bucks I had shelled out for the unit, I wasn't overly impressed right out of the box. There were only two attachment points, plates that bolted to the Transom.

Well, to make a long story short, two years ago while slamming across the bounding main, the A Frame vertical structure parted company with its mounting plates and migrated forward with great force assaulting me about the head and shoulders. The fact that I remained conscious and did not require stiches in my scalp is a minor miracle.

I contacted the dealer in the States and got a duhhhh response. I have not yet reinstalled the unit due to the fact that when I got the price for re-welding the main stanchions and adding what should have been there to begin with.....secondary support arms, I did need stitches in my scalp.

Anyone with any experience on a REAL A frame structure for a 4.7 Searider? I think somewhere along the line I emailed Avon and got no response.....

My attempt to post a photo failed...I'll try again in reply to this message.

If this unit originated with the OEM, and there is anyone out there with contacts, they should be aware of the failure and the need to "enhance" the structure.

Tomas · 21 October 2006, 17:27

Now residing in the meadow where it can do no further damage....

No luck with the pic. If anyone wants to see it, I'll try again later.

Stoo · 21 October 2006, 20:42

Could corrosion have been a factor Thomas?

My original RIB was a 16' Hurricane. It used a simple 3" aluminim pipe as an A-frame that was also bolted to the inside transom. In addition though, there were two "legs" that were bolted to this pipe perhaps 12" from the bottom. These ran down on a 45 degree angle to the deck where they were bolted to plates of aluminum that were perhaps 2" x 4", and these were bolted into the deck itself. These legs were about 3/8" thick, perhaps 1 1/2 " wide and maybe 15" long. They provided very strong support against the constant fore-aft stesses. The A-frame itself had several brackets welded to it that supported running lights and antennas.

I had that boat many years, and it is still around town two or three owners later and still going strong... It must be 15 years old at least, but only ever used in fresh water.

My current set up (a Hurricane 590) has a self-righting assembly, so the frame is extremely strong.

Tomas · 21 October 2006, 21:14

FThanks for your comments. Corrosion....well one would assume the unit was fabricated for a corrosive atmosphere.

What you described is what I was lacking from whoeverf supplied my A Frame....a second "branch" attachment, perhaps at a 45 degree angle back to the deck.

Let me again try to send a photo of the failed system....

Nos4r2 · 21 October 2006, 21:17

tomas set up an account at photobucket.com and it'll give you a link you just paste in to post a pic.

Stoo · 21 October 2006, 21:31

Quote:

Originally Posted by Tomas

What you described is what I was lacking from whoeverf supplied my A Frame....a second "branch" attachment, perhaps at a 45 degree angle back to the deck.

I should have clarified that the "legs" were not bolted through the A-frame itself as this would have weakened it. The frame had two small flanges welded to it and these legs were bolted to the flanges...

It was simple but effective.

Tomas · 22 October 2006, 04:05

Here's the photo of the failed A Frame. I thought it was a 640 x 480 but when I look at properties it exceeds to 200 kb limit and won't post.

Link:

http://i118.photobucket.com/albums/o...3/IMG_0241.jpg

Stoo · 22 October 2006, 04:18

I presume you could get some legs welded to that without too much difficulty... It does look fairly light though doesn't it....

Tomas · 22 October 2006, 11:16

Yes, it is very light. The tubing, although I didn't measure is I think .032 wall, .060 max or 1/16 inch. Given the fairly heavy plate at the apex and the nav lights, that's a lot of force on such a minimal tube base. Obviously too much force.

Hey, give my lukewarm response from the dealer and no response from AVON, I was hoping they might pick up this tread, have regrets and ship me a brand new commercial A Frame with Self Righting Bags! Yea...and have it shipped via St. Nicholas!

Actually, I'm in the market for a replacement. The tubing is so light on the rig I have I just don't trust it even with mods. Anyone over there know who fabs quality frames for RIBs?

I could find a fabricator in the states but as evidenced in the thread

Why Haven't Americans Gone Rib Crazy?

there is likely no one producing them and I don't want a first off design...I already have one lump on my head!

Tomas

Stoo · 22 October 2006, 16:21

I wish I had a picture readily available of my old boat, because that frame was a very simple affair. I suspect any good muffler shop with a pipe-bender could easly fabricate one if you sourced the pipe. I suppose that there may be limited fabricating options where you are.

I had two antennas , a GPS antenna, running lights and a radar reflector on mine and it supported all very well.

I'll try to locate a photo and scan it so you can see it first hand...

Tomas · 22 October 2006, 18:00

Fab capability is very limited here and the cost is just unimaginable. With a good pic possibly I can put a drawing together and have it made up North.

I saw diving in your profile....we do a lot of that here. The entire N shore of St. Croix is a cliff. It drops off suddenly to 6,000 ft and between here and St. Thomas, 32 nautical miles, it is 19,280 ft. deep.

I guess you must dive in August or resort to going in through a hole in the ice! What kind of stuff do you do...is the water clear?

tomas

Stoo · 22 October 2006, 18:20

We dive primarily in the Great Lakes. I drag my RIB from eastern Lake Superior to the St. Lawrence River, but home base is Tobermory. I log about 4 - 5000 km on my boat trailer annually!

Our diving is almost all wreck diving and the best ones are in the 100' to 200'+ range. The St. Lawrence has a lot of fish... large and smallmouth bass, pickeral, pike, sheepshead, perch etc. Because of the current, there is no thermocline there, which the fish appear to prefer. In the Lakes themselves, the water is pretty cold though. Below 25m, it never gets above 3 degrees C. Generally, we "hardcore" types are in the water by late April when the ice leaves and I will likely be able to get out until late November, although it gets pretty unpleasant... a lot of wind with increasing precipitation in the form of sleet, rain, snow. Strictly drysuits! We travel to the Carribbean every year to defrost, but have never made it to your area. I worked in the Bahamas and Grand Cayman in my mis-spent "yoot" teaching and guiding and on occasion, I regret my decision to come back to Canada. As retirement looms in the next 10 years, I am starting to consider southern options for part of the year anyway!

I have been corresponding in PM with "Diver" who dives in the Baltic and the diving sounds similar. There are some great pictures of some of my favorite sites here... http://www.wrecksandreefs.com/newpage1.htm (in the Great Lakes section)

It might take me a few days to locate a picture of the old boat, but I will see if I can find something....

Tomas · 22 October 2006, 18:34

Yes, it's different up there. A few years ago I was in the maritimes and took a small zodiac with me. We were East of Prince Edward Island and determined to haul our gear out to a small island which was three miles or off shore. There had been a lot of fog and drizzle but the morning we decided to go it had cleared. We decided to leave all the camping gear behind and do an exploratory. The island was beautiful, uninhabited and had a large horseshoe bay with sandy beach. We decided to go back, get gear and return. Well, on the way back the damn fog rolled in so fast that pretty soon we were blind. I wasn't worried about finding the mainland but at about that time what I guess was a sea lion rolled up out of the water right next to the boat and was about four times larger than we were. It scared the CRAP out of my wife and I admit thrilled me as well. He could have tossed us with the slightest effort.

The fog remained which allowed us not to admit defeat at the hands of sea mammals and we stayed the next two nights in a room!

IBWET · 23 October 2006, 16:02

Quote:

Originally Posted by Tomas

Here's the photo of the failed A Frame. I thought it was a 640 x 480 but when I look at properties it exceeds to 200 kb limit and won't post.

Link:

http://i118.photobucket.com/albums/o...3/IMG_0241.jpg

Looks like a run over tesco trolley.

jyasaki · 23 October 2006, 19:04

These things aren't really rocket science. It is simply a structure that mounts to the boat, carries a small parcel of mass, needs to be designed and mounted so as to withstand vibration from slightly above normal operation.

Can't tell from the pic, but is the tube stainless? And how about the bases?

Did the welds at the tube-to-base joint fail, or did the weld hold and the tube fail? (That'll tell you if it was a poor welding job, or if the design was not vibration proof.)

In either case, a good welder should be able to re-integrate the arch and plates in just a few minutes. Whether or not it would fail again is another matter, though.

The case for knees is a good one; it will prevent fore/aft flexing at the welds, which is probably what took it apart in the first place. Another solution would be to add some clamps further up the tubes to secure them to the transom (assuming they mount a ways down. You're trying to change the harmonic resonance of the free-standing tube.)

Good luck;

jky

Tomas · 24 October 2006, 17:36

[QUOTE=jyasaki;171077]
Can't tell from the pic, but is the tube stainless? And how about the bases?

Tomas · 24 October 2006, 17:43

Last post could use a message eh!

It's stainless and was it looks like chrome plated. The tubes failed three inches or so above the plates. I have not opted to add "knees" to this rig because the tubing is so light and the plate, etc. at the top so heavy. Fabricating here from scratch is out of the question. We're only 84 square miles and lie 1,200 miles SE of Miami, Florida.

I was hoping someone had knowlege of who fabricates real A-Frames and may have the SeaRider configuration. I can only assume that Avon had a hand in the bad unit I received since it came from their facility directly to me. I'm also surprised that they failed to respond when I informed them of the accident and suggested they look into it. Anyway, enough bitching but if anyone else on this site had that configuration....better purchase a helmet!

Thanks for your comments.

Tomas

pathalla · 25 October 2006, 03:36

Quote:

Originally Posted by Stoo

We dive primarily in the Great Lakes. I drag my RIB from eastern Lake Superior to the St. Lawrence River, but home base is Tobermory. I log about 4 - 5000 km on my boat trailer annually!

Our diving is almost all wreck diving and the best ones are in the 100' to 200'+ range. The St. Lawrence has a lot of fish... large and smallmouth bass, pickeral, pike, sheepshead, perch etc. Because of the current, there is no thermocline there, which the fish appear to prefer. In the Lakes themselves, the water is pretty cold though. Below 25m, it never gets above 3 degrees C. Generally, we "hardcore" types are in the water by late April when the ice leaves and I will likely be able to get out until late November, although it gets pretty unpleasant... a lot of wind with increasing precipitation in the form of sleet, rain, snow. Strictly drysuits! We travel to the Carribbean every year to defrost, but have never made it to your area. I worked in the Bahamas and Grand Cayman in my mis-spent "yoot" teaching and guiding and on occasion, I regret my decision to come back to Canada. As retirement looms in the next 10 years, I am starting to consider southern options for part of the year anyway!

I have been corresponding in PM with "Diver" who dives in the Baltic and the diving sounds similar. There are some great pictures of some of my favorite sites here... http://www.wrecksandreefs.com/newpage1.htm (in the Great Lakes section)

It might take me a few days to locate a picture of the old boat, but I will see if I can find something....

great link stoo!