Something on radios

[Borys]

Ahoj!
State of the art 1912 radio ship board radio set:

"The Titanic's "wireless" equipment was the most powerful in use at the time. The main transmitter was a rotary spark design, powered by a 5 kW motor alternator, fed from the ship's lighting circuit.

The equipment operated into a 4 wire antenna suspended between the ship's 2 masts, some 250 feet above the sea. There was also a battery powered emergency transmitter.

The main transmitter was housed in a special room, known as the "Silent Room". This room was located next door to the operating room, and specially insulated to reduce interference to the main receiver.

The equipment's guaranteed working range was 250 miles, but communications could be maintained for up to 400 miles during daylight and up to 2000 miles at night."

A pity no mention of weight:
http://titanic.marconigraph.com/mgy_wireless.html

[The Rock Doctor]

I imagine the height of the wire had a fair bit of influence on the range of the system...

[Borys]

Ahoj!
And I now remember that the German 1913 GTBs were nicknamed Christmas trees for their aerials.


Borys

[maddox]

I reserved 50 to 100 tons misc weight on my own designed warships to accomodate a short or long ranged Marconi.

Most people did simular things, without enforcing it in a rule.
With 1 exception.  Somewere on the Japanese Islands there must be a half plundered marconi factory that did build 0 weight Marconis. 

[Borys]

Ahoj!
At the very least that article gives me some indication of ranges. Big sets on battleships can be EXPECTED to transmit up to 250 miles, might do so up to 400, and at night - if they are looky, very far ...

Borys

[Carthaginian]

Well, here's something one one a bit later... from 1914; total weight, just under 200 lbs:
http://earlyradiohistory.us/1914mwt.htm

Wireless-Telephone Set
    A radio-telephone set which is designed for an oversea working range of 50 km (31 miles) between ship aerials 100 ft. high and having 200-ft. spans is being placed on the market by the Marconi Wireless Telegraph Company, Woolworth Building, New York.
    The set comprises a transmitter and receiver, overall dimensions 22 in. by 18 in. by 17 in. and weight 59 lb.; five cases of dry batteries, over-all dimensions of each case 21 in. by 18 in. by 5.5 in. and weight 70 lb.; one 6-volt, 80-amp-hour storage battery, weight 38 lb.; one switchboard, over-all dimensions 10 in. by 10 in. by 3 in. and weight 5.5 lb., and one receiving battery, over-all dimensions 9.5 in. by 17 in. by 5 in. and weight 20 lb. The set is also equipped with the following accessories and spare parts: two microphone cases and six spare microphone cells, six transmitting valves (double filaments), six receiving valves, one induction coil, one aerial tuning inductance, high-resistance telephones, one set of six crystals set in cups, connecting plugs and leads, six tuning lamps and small dry batteries for microphone and crystals.
    The transmitter consists of a specially constructed valve shunted with condensers and induction coils in such a way that a continuous stream of oscillations is produced. The frequency of these oscillations is controlled by means of variable ebonite condensers. The oscillations are induced into the aerial wire through a variable coupling, any tuning required being effected by means of the tuning lamp provided. A simple switch is used to change from talking to listening. This switch can be controlled from a distance in case the microphone is not near the set. A low-voltage current is used to heat the filaments of the valves, and for this purpose an 80-amp-hour accumulator is provided.

I shall work the rest of the night to find more details for older sets, but it appears that with 50 tons we might be overcharging for communications equipment just a teency-weency bit. ;)

EDIT: I was wrong on the weight... it was closer to 500 pounds. Still, a lot lighter than expected. Even with several sets of spare parts, you're only looking at about a ton.

EDIT: A second link from the same site, that describes an aircraft set with a 400' trailing wire antenna (operating from unknown altitude) being heard for over 100 miles with a set that weighed in at only 100 lbs:
http://earlyradiohistory.us/1963hw23.htm

Hooper's next action was to direct the Naval Radio Research Laboratory to prepare a study of the probable range of an aircraft radio transmitter of a weight not exceeding 100 pounds. On 13 May 1916 Austin submitted the following report:
...
...
   3. Trailing wire 400 feet long, plane as counterpoise. Weight of set, 100 pounds; distance 75-100 miles.

[maddox]

The misc weigth isn't only the marconi set, but let us see from N-verse point of view for a marconi on a warship.

1906, not all the navies had marconies. Nor had all the ships from Marconi using navies this device on board. So, lets think Springsharp does not have this included.

For a larger warships, a 100 km range set won't do. So , let's take the 5 kw, 400 kilometer range set.  2 sets and 1 in spare parts- it's not as if UPS can drop a spare part any time soon.
So even designed for ruggedness and easy repairability. Just take 1 ton for all.

What we need is a sheltered space large enough to put the transmitter and reciever in.
Steel and wooden radio room, 4*2*2.2 meter. 10mm thick steel plate. approx 20 tons.

A reliable powersource. A few Dry cells won't cut the cheese for weeks on station. 1 ton of fuel extra for the boilers or for a auxilary power supply.

To have a full compliment to man this equipment 24H a day, 7 days a week. 3 Marconi operators + supplies. 6 kg a day pp (including  fresh water or the powersource to make it) for 20 days . Including gear, 1 ton.

There you go, 23 tons.  Just to have a marconi plunked on a battleship, with a range of 400 km. (or 1600 in ideal circumstances)

[Carthaginian]

The misc weigth isn't only the marconi set, but let us see from N-verse point of view for a marconi on a warship.

1906, not all the navies had marconies. Nor had all the ships from Marconi using navies this device on board. So, lets think Springsharp does not have this included.

For a larger warships, a 100 km range set won't do. So , let's take the 5 kw, 400 kilometer range set.  2 sets and 1 in spare parts- it's not as if UPS can drop a spare part any time soon.
So even designed for ruggedness and easy repairability. Just take 1 ton for all.

What we need is a sheltered space large enough to put the transmitter and reciever in.
Steel and wooden radio room, 4*2*2.2 meter. 10mm thick steel plate. approx 20 tons.

A reliable powersource. A few Dry cells won't cut the cheese for weeks on station. 1 ton of fuel extra for the boilers or for a auxilary power supply.

To have a full compliment to man this equipment 24H a day, 7 days a week. 3 Marconi operators + supplies. 6 kg a day pp (including  fresh water or the powersource to make it) for 20 days . Including gear, 1 ton.

There you go, 23 tons.  Just to have a marconi plunked on a battleship, with a range of 400 km. (or 1600 in ideal circumstances)

Please don't get me wrong... I wasn't saying that the weight was inconsequential. I was just trying to make a reasonable argument for lighter-than-listed weight requirements for a wireless set. I FULLY agree that a minimum shipboard set would be a 10-ton addition to a ship for 150 km or so transmission range. This would likely be something found on a scout cruiser; it's just enough to get back to the main battle group. Anything like what a fleet flagship would require (call it 400-500 km ideal) would easily cost the 25 tons that you listed. Perhaps a set made to reach 800-1000 km (3200-4000 km ideal) reliably would be 50 tons.

Set it up like that, and we have some general weight requirements, which is all I was trying to suggest.

[Borys]

Ahoj!
Good suggestions.
ADDED LATER:
Included in guidelines
Borys

[maddox]

Carthaginian
There was no requirement. Just a bit of common sense.

Unfortunatly, once a question like this is asked, and "handwavium" answer is given, some people tend to abuse the "common sense". And that is when a rule had to be made and  put in concrete.

[P3D]

Maddox' calculation is a bit too conservative - 4-5mm steel should do for the walls, but that's still 10t.

Destroyers and protected cruisers did not have much redundancy built-in yet - especially the former. IMO they could get away with say ~5t. Weight savings on having lower aerials, only spare batteries in case of power failure, etc.

[Borys]

Ahoj!
Maddox's designs do have a "built to last" quality about them.
Why use 1/4 inch steel if you can use 1/2 inch :D

Borys

[P3D]

 ???
Because the deck would fall in from the weight?
;)

[maddox]

I seem to have a bit of steel experience irl.   5mm steel plating without a lot of reinforments will look very good after a storm.
Even 20 foot containers are made from 6mm corrugated sheet steel of good quality.
Weight, tarra between 3500 and 4700 kg.

Also, what I described was an add on setup for a battleship. Not an integrated part.

[P3D]

US battleship construction used 1/4" extensively in bulkeads. I think they'd rather use 5mm with some beams as external or internal reinforcements agaist the bulging. Saving salf the added topweight for the cost of some bracing would be priority for any naval engineer.

Next time when I visit any warship I will ask.