Check your trailer wheel nuts!

[Graham W]

Attached a photo of a warning sticker on my trailer wheel arches, together with what happens if you ignore this advice (underneath the sign).

I was coming back from Bala when I heard a strange rumbling noise from the trailer and  stopped immediately.  One bolt was missing altogether from the nearside wheel and the other three were hanging on by a thread (literally) and ready to fall out too.  I shudder to think what would have happened if the wheel had dropped off at 50 mph.  As I didn't have spares, I tightened the remaining three bolts and limped the rest of the way home, stopping frequently.

What I don't understand is why it happened.  Since swapping to 13" wheels, I had assumed that tightening the bolts to 65 lb Ft would be sufficient.  After all, that level of tightness got me to Corfu and back several times on 10" wheels but with wheel nuts rather than bolts.  Perhaps bolts are more prone to loosening themselves?

[Peter Cockerton]

Graham

I have heard of this before, couple of possibilities, the new wheels had paint on the seating area of the hole in the wheels, the paint breaks up and the friction seating between the bolt and the wheel is impaired. The bolt then vibrates loose.

Another possibility is the seating between bolt and rim hole is not matched, I.e the angles are different, the friction grip is then not achieved.

Peter

[Graham W]

Peter,

Your flaking paint idea seems very plausible as the wheels are new - I'll take another look when the packet of replacement bolts arrives.  I'll also make sure both sides are properly seated and check everything every trip from now on.

[Tony]

Hi Graham.
A nasty experience!
As they are bolts, rather than nuts, would spring or star washers help? What do the engineers out there suggest ?

[Rob Johnstone]

Hi Graham - I wonder if the brake drum got heated enough (through the action of the brakes) for expansion to allow the bolts to become loose? If you are going to change from bolts to studs, make sure the studs are welded to the drum.
Rob J

[Graham W]

Rob,

Another plausible idea - the trailer brakes get a really good work out crossing the Berwyn Mountains to Bala.  It would suggest extra heat on one side only from a poorly adjusted brake mechanism?

[Graham W]

My replacement trailer wheel bolts have arrived, so I shall be carefully checking everything in the wheel and brake area.

In the meantime, I have been having a look around t'interweb to see how common a problem this is.  Most of the examples of wheel loss that I came across were due to over-tightening of the wheel fixings, causing strain and sudden shearing of the bolt or stripping of the threads.  Jeff Curtis posted an example of the latter on the forum a while back http://www.swallowyachtsassociation.org/smf/index.php/topic,559.msg3259.html#msg3259

The National Trailing and Towing Association have a page on wheel nut tightening here http://www.ntta.co.uk/law/trailers/wheels_tightening.aspx.  It includes this recommendation "It is ESSENTIAL [their emphasis] that the torque settings are re-checked after the first 25 miles or 50 km and subsequently before each journey."

The UK Government (pro tem) have published a wheel maintenance leaflet for lorries with a jokey title that seems to apply equally well to boat trailers https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/322067/careless-torque-costs-lives.pdf.  It includes this explanation of one of the causes of wheel loss:
"• early relaxation of tension in the wheel fixing after initial tightening following wheel refitting; the wheel stud or bolt is like a very stiff spring which stretches when the fixing is tightened; settlement, even with the vehicle stationary and not subject to vibration, reduces the stretch and the wheel is not clamped sufficiently tightly
• to correct this relaxation, the wheel fixing should be retightened to the recommended torque after 30 minutes if the vehicle is stationary or within 40 kilometres (25 miles) to 80 kilometres (50 miles) if the vehicle is used"

My main take on all this (and other posts about trailer brakes, tyres and bearings on the forum) is that no matter how careful you think you are being and how well specified your trailer is, it is more likely to cause you significant grief than your boat!

[Graham W]

Before and after (below). One of the hub female threads seems to have been damaged too.

[Peter Taylor]

I've just had my CLH BR20 trailer converted to braked and managed to get a "User's Handbook" from Andrew at CLH.  Given that nowadays if you buy a climbing karabiner it comes with a 25 page manual, the CLH "handbook" is refreshingly short at 2 sides of an A4 sheet... however it would be an advantage if one came with the new trailer!

For my braked 13" wheels held on by 4xM12 bolts (19mm A/F socket size) the torque specified is 65lbft, 88 Nm. The tyres are 165R13 with maximum inflation 65psi.  It seems to be only the 10" tyre for which 35 psi is specified.  The specified torque agrees with what I've seen for similar wheel bolts on other makes of trailers.

On the subject of trailers, in a thread I can't now find, there was the question of the swinging arm jamming against the bow rather than swinging.  In the video of Matt recovering his BC23
https://www.youtube.com/watch?v=vhvADf6BCOw the trailer is the larger CLH type and the swinging arm has two extra central rollers compared to my BR20 trailer which cause the swinging arm to move out of the way just at the right moment.  You can just see them in the attached screen grabs.
Peter

[Rob Johnstone]

Hmm. Dealing with Vagabond is not so easy!

I wonder how many people Matt had out of shot to help him push Go Lightly off the trailer. The technique that I have to adopt with Vagabond is to make sure all the straps are loose, reverse smartly down the slip and brake hard at the last minute, just before the wheel are up to the hubs. Three attempts is usually enough for Mo Mentum to get Vagabond afloat.

Unfortunately, the process can't be reversed, and getting her out requires very strenuous winching. It helps to shift weight to the back of the boat to lift the bow. Or to pay for a lift out!

Rob J

[Rob Johnstone]

Back on tyre sizes. It seems that you have to be a bit careful about the type of tyre you have, not just the size but also the specification.

As well as the tyre size 165R13C, there are at least two other important parts of the tyre specification. There's a pair of numbers (something like 94/96 or 92/94) that specify the load carrying capacity of the tyre and there is a letter which specifies it's maximum speed. There are details of both of these at  http://uk-trailer-parts.co.uk/trailer-tyre-load-index.

The snag is that I can't find a 13 inch tyre that had a load capacity to carry Vagabond and trailer!

All of this research has arisen because, once Vagabond was afloat at Mylor, I noticed that one of her trailer tyres had worn unevenly and the metal radial band was exposed on the inside edge. Investigation showed that the trailer axle was no longer at right angle to the centre line of the trailer. Whilst towing from Inverness to Fort William, the inside trailer wheel went into a particularly deep pothole (this caused the inside of the wheel rim to bend and the tyre to deflate - but that's another story) and I suspect this impact made this side of the axle slide on the U bolts. More work in progress....

Happy trailer sailing!

[Peter Cockerton]

Hmm. Dealing with Vagabond is not so easy!

I wonder how many people Matt had out of shot to help him push Go Lightly off the trailer. The technique that I have to adopt with Vagabond is to make sure all the straps are loose, reverse smartly down the slip and brake hard at the last minute, just before the wheel are up to the hubs. Three attempts is usually enough for Mo Mentum to get Vagabond afloat.

Rob J

Rob

Can't you lower the back rollers on the trailer to increase the boat angle on the trailer, this has worked on my BR20 and recently a BRe i launched, recovery still down to weight of boat though, do you have a two speed winch fitted.


Peter

[Graham W]

I've just had my CLH BR20 trailer converted to braked and managed to get a "User's Handbook" from Andrew at CLH.  Given that nowadays if you buy a climbing karabiner it comes with a 25 page manual, the CLH "handbook" is refreshingly short at 2 sides of an A4 sheet... however it would be an advantage if one came with the new trailer!

For my braked 13" wheels held on by 4xM12 bolts (19mm A/F socket size) the torque specified is 65lbft, 88 Nm. The tyres are 165R13 with maximum inflation 65psi.  It seems to be only the 10" tyre for which 35 psi is specified.  The specified torque agrees with what I've seen for similar wheel bolts on other makes of trailers.

On the subject of trailers, in a thread I can't now find, there was the question of the swinging arm jamming against the bow rather than swinging.  In the video of Matt recovering his BC23
https://www.youtube.com/watch?v=vhvADf6BCOw the trailer is the larger CLH type and the swinging arm has two extra central rollers compared to my BR20 trailer which cause the swinging arm to move out of the way just at the right moment.  You can just see them in the attached screen grabs.
Peter

Peter,

Is the CLH manual in a form that can be published?

The swinging arm problem is discussed here http://www.swallowyachtsassociation.org/smf/index.php/topic,1141.msg7954.html#msg7954

[Julian Swindell]

I had great difficulty getting my BC20 off her trailer at Mylor. Eventually a Good Samaritan came and added his weight and we pushed her off. When I relaunched back at Poole I used the old trick which Matt reminded me of, taking the winch strap around a roller (or a cross member in fact this time) and back to the towing eye. Then you can winch the boat off, which worked very successfully. I always used to launch my (heavy) Winkle Brig this way, and the trailer for that actually had a second winch just for doing this.
I hate trailers!

[Andy Dingle]

I have some sympathy with you Rob. 'Equinox' (BC23) is quite reluctant too to get back into her natural environment off her trailer. The problem it seems is no matter how they are configured the rollers always lay 'behind' the bilge runners which causes a fairly effective brake to her rolling off smoothly. Am still working on this problem myself - but as I am now happily ensconced on a pontoon mooring this matter has become less of an issue until next winter when I will resort to launching off the trailer again.
I have thought up a plan for back winching which is the obvious solution and easily done and takes the strain out of things - (Julian has already suggested this I have just seen) and as Peter suggests, raising the front rollers and lowering the rear ones helps somewhat, failing all this, old fashioned floating her off works, but of course this involves dunking your expensive brakes and bearings.

Re the issue of the rear swing arm not performing as required. I too have the central rollers on the arm and have no problem at all getting the bows mounted appropriately. These rollers could be retro fitted quickly and cheaply (I recall some BR20 and BRe owners having this problem too?). In fact I had recently been looking at video of the cracking North Quay Spitfire 18 ..  this you tube footage clearly shows these central swing arm rollers in use on their trailer to aid in recovery...

https://www.youtube.com/watch?v=LSjqVhH0Ub4

I have a twin speed recovery winch, a Dutton-Lawson Model 2500A, when your right arm has had quite enough, it is so good to just 'change gear' and let your pride and joy easily slip up the trailer (works with the boat too!!)  - half the speed, but half the effort.

Andy

PS My apologies couldn't make Mylor - I was inordinately delayed out in the sub continent - hence I missed the tide on the slip that requires hw springs and the yard hoist was the working end of a £ton a pop .. etc etc..