DSC Correspondence with MCA

[tome]

I sent the following to MCA
[ QUOTE ]
Re: DSC Alerts

Dear Sirs

I have been using a DSC radio for the past 2 seasons, and am writing to express my concern at one aspect of the DSC specifications: Alarm volume.

The problem is that the specification does not allow the alarm volume to be altered. On channel crossings, this can cause many loud alarms (eg Joburg routine traffic) which make it impossible for the off-watch to sleep. We recently crossed Lyme Bay and had to endure an RN ship putting out DSC alerts every 15-20 minutes to provide repeated firing range information.

Unless the specification is altered to allow control of the alarm volume, we will have no choice but to switch the set off on night passages as lack of rest for the off-watch crew could eventually jeopordise the safety of our boat.

We currently use a non-DSC handset as a backup and this is switched on when the DSC set is silenced. However, it appears to defeat the object of DSC.

With the old VHF sets we could reduce the volume on channel 16 without missing any safety or distress traffic. As an electronics engineer, I believe that the DSC specification is just plain wrong and I implore you on behalf of us users to bring pressure to change the specification to allow volume control of the alarm.

Yours sincerely


[/ QUOTE ]

To which I had the following reply

[ QUOTE ]
I am afraid I can only offer sympathy - as a Class D user myself, I know exactly the problem. The international standard IEC 62238 has a better form of words than the European one:

Acoustic Alarm Power (IEC 62238)

The acoustic alarm shall initially be of a power that it is clearly distinguishable, but not interfere with, radiotelephone communications. If not manually cancelled within 10 s, the power should rise to a level of at least 80 dB(A) at a distance of 1 m from the equipment before automatic cancellation.


4.2.2.6.3 Acoustic alarms (EN 301 025)
The acoustic power of an alarm shall be at least 80 dB(A) at a distance of 1 m from the equipment.

Both, though, will end up with a piercing noise before the on-watch can get to it. Manufacturers do raise this issue at the appropriate fora, but the SAR lobby is adamant that this alert must be heard. Although against the Radio Regulations, I am aware that because of the problem you raise, many people turn the DSC off. I am sorry I can't offer more.

[/ QUOTE ]

I'm not sure where to go from here!

 

[Phoenix of Hamble]

Tome,

I have been thinking about the technicalities of this issue and the reality is that the alarm volume is neccessary for emergency calls, but could maybe reduced on urgency and securite calls, perhaps a slightly lower alarm volume, or an increasing scale as per the international standard, with a 20sec period before escalating... giving on watch time to turn it down.. or perhaps selective alarms, being presented to external speakers only, and not internal...

There are lots of potentially intelligent solutions to this problem that would allow and encourage the continued use of DSC.... whereas the present intransigence of the SAR folks will probably result in limited adoption in UK waters by pleasure users.... ultimately making the SAR job harder....

IMHO anyway....

 

[Gunfleet]

Whoever drew up the reg obviously finds it difficult to conceive of a situation where the radio is neither a) on a bridge or b) in a communications room. Like all legislators, once the mistake is made the last thing they are going to say is 'whoops, better change that', so don't expect improvement any time soon. FWIW I have a Navico VHF that I bought the add on DSC controller for... then after one season decided to unplug it and go back to vanilla vhf.

 

[Evadne]

It sounds like choosing not to upgrade to DSC was the right decision. There are times when the continuous chatter on CH16 is bad enough, but an alarm going off at least every hour is, very quickly, going to be ignored or switched off. An audio alarm that elicits the same response for a mayday as for a traffic list or weather forecast is very badly designed.

 

[Mirelle]

Good answer from the \"Southampton Lubianka\"

They are a good bunch, actually.

The problem is that the standard was cast in stone by the IMO, who made the ghastly mistake (since repeated over electronic chart display and information systems!) of setting detailed technical standards in an area where the technology is rapidly changing. You are correct in that nobody foresaw the application to pleasure craft.

DSC is not worth while, IMHO.

 

[ParaHandy]

Re: Good answer from the \"Southampton Lubianka\"

since when? this place was (up to now, I thought) known by the (diminishing) half of the MCA staff who don't work there as the pink palace. Named after Gen Galtieri's HQ in Argentina ...

 

[Robin]

Tom

At least now someone from official circles has acknowledged that there is a problem. How to solve it and in what timescale is another question!

Like you I thought about using our handheld as the receiver but a) It means it wouldn't be immediately ready with fully charged batteries if needed in an emergency (we keep it in our grab bag when offshore) and b) it doesn't have the same receive range as using the masthead aerial, so some broadcasts like weather might be missed. I have toyed with the idea of re-installing our old set as a secondary for receive only especially as we already have a second VHF aerial on a stern gantry with it's lead located by the set and ready as a backup. I even thought of buying a second cheapie DSC for this listen only purpose and not entering the MMSI so it wouldn't be DSC 'activated'.

And all we really needed was to be trusted to set the alarm volume ourselves, as we would for the traffic data transmissions on modern car radios.

Robin

 

[Mirelle]

2003

So christened by a columnist in "Lloyd's List" in 2003, when taking the Michael out of the Code of Safe Practice for Merchant Seamen. Several denizens informed him that they felt it appropriate!

 

[webcraft]

I was an accidental early adopter of DSC because I won a set in a competition and sold my old Sailor set for £50 - a fact I now may come to regret.

At the moment there is no problem whatsoever with non-distress DSC calls up here in W. Scotland, and we did not experience any problems in our trip round Ireland last Summer. If we do experience problems in the future the set will be switched off and we will therefore not be monitoring any emergency frequency - which I think will be a pity, but there you are. I certainly won't flatten the batteries on my hand-held unnecessarily because of the intransigence of the legislators.

I go sailing for pleasure, not to be harassed by beauracracy and technology - I can get as much of that as I want onshore.

- Nick

 

[duncan]

tome - seems to me the only consistent course of action to keep tht eimportant people happy (legislators, manufactures and SAR....) is to ban any routine message sender from using the alarm function - problem solved; both now and in the future.
Given that it appear accepted that users are actually switching off (which has negative implications to the SAR functionality) such a step should be pursued by said all powerfull SAR lobbist's.

 

[DRW]

Re: Good answer from the \"Southampton Lubianka\"

Spring Place - official,
Spring Palace - unofficial,
Palace of Malice - usual.

 

[Nickel]

Anyone tried voiding their warranties and getting in to the case to install a volume control?

 

[ianwright]

Stop buying DSC sets, we don't need them, they are not even a fun bit of kit to impress our friends with. If you bought one by mistake send it back to the maker and tell him the alarm trips your pacemaker.
Boycott the damn things!

IanW

 

[Phoenix of Hamble]

Has anyone seen any coverage of this issue in the magazines?

I would have thought a bit of good old fashioned publicity would help focus the MCA's attention....

Kim... is this something that should be mentioned to Ms Norbury and Mr Gelder.... its clearly a very important topic given the frequency and verocity of posts on the subject....

Failing that, the nationals always love a bit of 'Government implements law that doesn't work' type news...... how about an angle... 'lives endangered by civil servant/government intransigence'....

 

[tome]

I've refrained from commenting so far on the various suggestions (I am indeed tempted to open my set and wire in a volume control) and have instead sent the following response to MCA:

[ QUOTE ]
Thanks for your reply, and it does reassure me to know that MCA aware of the problem. I have anonymously posted both my email to you and your response on the Yachting & Boating World forum of which I'm a member, see http://www.ybw.com/forums/showflat.php/Cat/0/Number/673219/an/0/page/0/gonew/1#UNREAD.

There is a lot of interest and concern regarding DSC alerts. It was actually at the suggestion of one of the manufacturers UK representatives via the forum that I contact MCA to make my point. Having done that, it begs the question of where to go next. You mention the SAR lobby, but surely this is a part of the MCA?

I therefore wonder if you could suggest who, as users, we should contact next to put our message across?

Regards
Tom

[/ QUOTE ]

 

[Mirelle]

I thought I had explained that already

It is not within the MCA's power to amend this, as their answer makes clear. This is an IMO specification. Yes, it is a nonsense for pleasure craft, but we are dealing with a United Nations Convention here, which has been signed, ratified, and brought into force.

Nothing that the British Government can do, other than derogate from it, which most assuredly is not going to happen (for one thing, the IMO is the only UN Agency with its headquarters in London!) will change any part of it.

We are stuck with it.

 

[peterb]

Re: I thought I had explained that already

I doubt very much whether IMO would have called up an EN (European Norme) standard, but they may well have called up the International Standard. If the EN is being called up, then almost certainly it is being called up by a European body, not IMO directly.

From the MCA reply, it looks as if the IEC standard is appreciably better than the EN. At least it gives a possible 10 seconds in which to cancel the alarm before it becomes deafening.

Perhaps we might be better off in trying to get the European decision changed.

 

[Mirelle]

Quite so.

We commonly find this, in shipping matters.

But even a ten second delay is not much use on a boat.

 

[tome]

Re: I thought I had explained that already

[ QUOTE ]
We are stuck with it

[/ QUOTE ]

Homo sapiens ring a bell (or sound an alarm)?

 

[Robin]

Re: I thought I had explained that already

The 10 seconds is no use at all. By then the off watch crew is wide awake only to be blasted with phase 2 at full volume! In any case even outside of sleeping times you are still running up and down the companionway each time it goes off and I can't do that in 10 seconds from a sat down start.

I am coming firmly round to the lateral thinking solution, ridiculous as it is, of a 2nd non-DSC set as the 'listener', either the old set I still have or a new cheapy that I don't activate the DSC features on, ie by not entering an MMSI. In the meantime if anyone can invent an accessory controller, their first customer is waiting ready!

What a crazy world.

Robin