Orolia S4-1 S4 SART User Manual

Orolia Ltd S4 SART

User Manual

S4RESCUE SARTSearch And Rescue TransponderUser Manual
CONTENTSWarnings....................................................................................1General description...................................................................2SART principle of operation .....................................................2Installation .................................................................................4SART General Assembly...........................................................5Operating instructions ..............................................................6Self test facility ..........................................................................7Battery replacement..................................................................7Technical description................................................................8Function chart ...........................................................................8Dimensions................................................................................9Operation of marine radar for SART detection......................10Radar Range Scale ..................................................................................10SART Range Errors..................................................................................10Radar Bandwidth......................................................................................10Radar Side Lobes.....................................................................................10Detuning the Radar ..................................................................................10Gain.........................................................................................................10Anti-Clutter Sea Control............................................................................11Anti-Clutter Rain Control...........................................................................11Technical Specification...........................................................12Declaration of Conformity.......................................................13Limited Product Warranty.......................................................15
1Warnings• This SART is an emergency device for use only insituations of grave and imminent danger.• False alarms cost lives and money. Help to prevent them;understand how to activate and disable your equipment.• Read the complete manual before installing, testing orusing the SART.• The SART contains no user servicable parts. Return to yourdealer for service.• Dispose of this device safely. Contents include Lithiumbatteries; do not incinerate, puncture, deform or short-circuit.• This device emits radio frequency radiation when activated.Because of the levels and duty cycles, such radiation is notclassed as harmful. However, it is recommended that youdo not hold the radome while the SART is activated.• The battery in this device is rated Class 9 for transportationpurposes. Ensure compliance with all applicableregulations.
2General descriptionThe SART (Search And Rescue Transponder) is designed for survivor locationduring search and rescue operations.CARRY-OFF SARTSupplied as one integral unit. This is normally mounted in a bulkhead bracket(supplied) which is used to stow the unit on the mother vessel. On abandoning to asurvival craft the SART can be carried in one hand off the stricken vessel andmounted through a port in the canopy of the survival craft using the telescopic pole.The main body of the SART is high visibility orange thermoplastic, attached to thesealed replaceable battery pack by stainless steel fastenings. The joint is sealedagainst water ingress by an O-ring.Operation is by a rotating switch ring providing ON, OFF and TEST functions. TheON position is reached by breaking a security tab. The switch ring is spring loadedso that it returns automatically from the TEST position.The Lithium battery is fitted with internal overload protection and has a five yearstorage life. Non-reversible electrical connections are provided in the SART bodyand battery pack to facilitate battery replacement.Each SART carries a unique serial number on the label on the orange body.LIFERAFT SARTSupplied with or without mast. Normally is packed as part of the liferaft equipment.The mast version is mounted in the same manner as the carry-off version; theversion without the mast is intended to be hung from the highest point inside theliferaft.The SART itself is identical with the carry-off version.SART principle of operationActuating a SART enables a survival craft to show up on a search vessel's radardisplay as an easily recognised series of dots.RADAR (radio detection and ranging) is a device carried by most ships which isused to determine the presence and location of an object by measuring the time forthe echo of a radio wave to return from it, and the direction from which it returns.A typical ship's radar will transmit a stream of high power pulses on a fixedfrequency anywhere between 9.2GHz and 9.5GHz. It will collect the echoesreceived on the same frequency using a display known as a Plan Position Indicator(PPI), which shows the ship itself at the centre of the screen, with the echoesdotted around it. Echoes further from the centre of the screen are thus further fromthe ship and the relative or true bearing of each echo can be easily seen.
3The SART operates by receiving a pulse from the search radar and sending back aseries of pulses in response, which the radar will then display as if they werenormal echoes. The first return pulse, if it sent back immediately, will appear in thesame place on the PPI as a normal echo would have done. Subsequent pulses,being slightly delayed, appear to the radar like echoes from objects further away. Aseries of dots is therefore shown, leading away from the position of the SART. Thisdistinctive pattern is much easier to spot than a single echo such as from a radarreflector. Moreover, the fact that the SART is actually a transmitter means that thereturn pulses can be as strong as echoes received from much larger objects.A complication arises from the need for the SART to respond to radars which maybe operating at any frequency within the 9GHz band. The method chosen for theSART is to use a wideband receiver (which will pick up any radar pulses in theband), in conjunction with a swept frequency transmitter. Each radar pulse receivedby the SART results in a transmission consisting of 12 forward and return sweepsthrough the range 9.2GHz to 9.5GHz. The radar will only respond to returns closeto its own frequency of operation (ie. within its receive bandwidth), so a "pulse" isproduced at the radar input each time the SART sweep passes through the correctfrequency.A slow sweep would give the radar a stronger echo to deal with as the sweepwould be inside the operating bandwidth for a longer period. The delay for thesweep to reach the operating frequency may however lead to an unacceptablerange error, as delayed echoes appear to be coming from more distant objects.To minimise this problem, the SART uses a "sawtooth" response, sweeping quickly,then slowly for each of its twelve forward and return sweeps. At long range, onlythe slow sweeps, giving the strongest returns, are picked up. At close range,where errors are more important, the fast sweeps are also detected. As the firstsweep is a fast one, then the range error is minimised and should be less than 150metres.The timescale over which all this occurs is very short. Each "fast" sweep takesabout 0.4µs, each "slow" sweep about 7.5µs. The complete series of twelveforward and return sweeps is therefore complete within 100µs. Displayed on thePPI, the spacing between each pair of dots will be 0.6 nautical miles.On a long range setting, a typical radar will be triggering the SART everymillisecond - but only during the period that the rotating radar scanner is pointing inthe correct direction. Most modern radars use sophisticated noise rejectiontechniques, which prevent the display of echoes which are not synchronized withthe radar's own transmissions, so one radar will not normally be confused by aSART's response to a neighbouring radar.The SART indicates that it has been triggered by lighting an indicator LEDcontinuously (it flashes in standby mode) and by sounding an integral buzzer. If noradar pulses are detected for a period exceeding 15 seconds, the SART reverts to"standby" mode.
4InstallationThe preferred mounting location is inside the vessel, and protected from theelements, usually on the ship’s bridge wing. The SAR should be mounted where itwill not get in the way of day-to-day operations, but where it can readily beaccessed near an emergency exit in the event it is needed.Do not install the SART within the ship's radar beam.Fix the mounting bracket to a bulkhead in a convenient location. The recommendedfixing is by M5 marine grade stainless steel (eg A4/316) bolts; length is dependentupon application. The bolts should be secured with either stainless steel lockingnuts or stainless steel nuts with stainless steel shakeproof washers.Mount the SART, dome uppermost, onto the bracket by locating the lugs on theSART pole mount into the slots in the bracket. Push down the SART into place, andsecure with the Velcro strap.Figure 1Bracket mounting holes: 4 holes, 5.5mm diameter.NOTE: Safe compass distance 1.5m.
5SART General AssemblyRing for internalliferaft mountingRadomeOperatingswitch ringBattery packLanyardMountingpoleBulkheadMountingbracket(Velcro strap omitted for clarity)Velcro strap
6Operating instructionsRemove from bulkhead bracket:Release Velcro strap and lift SART from bracketTo switch on:Pull the security tab away from the body of the SARTRotate the switch ring clockwise (ie to the left) to the ON position markedby “1”To extend the telescopic pole:Grasp rubber cover at bottom of pole, and twist the pole to release it in thepole mount.Pull the pole down and twist to lock in place in the pole mountRemove rubber cover from bottom of pole; allow pole sections to drop.Lock sections together by twisting each section.To deploy in a survival craft (liferaft):Extend the SART supporting pole as detailed aboveTether the SART to a suitable point using the lanyard which unwinds fromits base.Inset the SART through the port in the canopyPosition the bottom of the support pole in the antenna pocketSecure the pole to the canopy support.Some survival craft have the SART already packed as part of the inventory. Ingeneral, these models of SART are not fitted with the support pole. The SARTshould be switched ON then suspended by its top loop from the highest point of thesurvival craft.Switch ringSecurity tabON
7Self test facilityRegular testing of the SART is advised. The duration of the test should be limited toas short a time as possible as the SART response may be received by othervessels which are within range.There are no operational differences between TEST and ON modes; the rotaryswitch must be held in the TEST position, on release it returns to the OFF position.1. Ensure compliance with all applicable Health and Safety instructions whenworking in proximity to a radar transmitter.2. Locate the SART within the line of sight of an operating approved marineRadar.3. Rotate the switch ring anticlockwise (ie to the right) to the TEST position, andhold it in this position.a) If the SART responds to the radar, the red light in the base of the SARTwill be continuously lit and the buzzer will sound every 2 seconds.b) If the SART does not respond to the radar, the red light will flash every 2seconds and the buzzer will not sound.4. Switch off the SART by releasing the switch ring; check that it returns fully tothe OFF position.Battery replacementThe battery should be changed 5 years from the date of manufacture shown on thelabel and routine test procedures should be carried out.It is recommended that battery change should only be performed by an authorisedMcMurdo service agent, in order that a complete assessment and integrity checkcan be performed. The replacement battery kit is McMurdo part number 86-630.Indicator lightTEST
8Technical descriptionA single switched antenna is used for both receive and transmit functions; theswitch normally connects the antenna to the receiver circuit. In the standby stateonly the receiver portion of the SART is powered to reduce battery consumption toa minimum. In this condition the indicator circuit causes the LED to flash onceevery two seconds.On receipt of a radar pulse the video amplifier and detector circuit causes the restof the circuitry to become active and the unit switches to transmit mode. In thiscondition the indicator circuit causes the LED to remain steady and the buzzer tosound every two seconds.The detection of a radar pulse causes the switch to connect the antenna to thetransmitter circuit. The output stage is fed by a Voltage Controlled Oscillator (VCO),whose frequency is determined by a sweep generator. When triggered by thedetector the sweep generator turns on the VCO and causes it to produce exactly 12forward and reverse frequency sweeps before shutting down again.If no radar pulses are detected for a period of 15 seconds the unit reverts tostandby mode.Function chartSART STATUS BUZZER RED LEDOFF OFF OFFSTANDBY MODE(TEST or ON) OFF FLASHINGEVERY 2 SECONDSACTIVELYTRANSPONDING(TEST or ON)ONEVERY 2 SECONDS ON
9Dimensions
10Operation of marine radar for SART detectionRadar Range ScaleWhen looking for a SART it is preferable to use a range scale between 6 and 12nautical miles. This is because the spacing between the SART responses is about0.6 nautical miles (1125 metres) and it is necessary to see a number of responsesto distinguish the SART from other responses.SART Range ErrorsThere are inherent delays in the SART responses; the SART has a trigger delayand may also have to sweep through the whole radar band before reaching thefrequency of the search radar. At medium ranges of about 6 nautical miles therange delay may be between about 150 metres and 0.6 nautical miles beyond theSART position. As the SART is approached the radar delay of the first dot shouldbe no more than 150 metres beyond the SART position.Radar BandwidthThis is normally matched to the radar pulse length and is usually switched with therange scale and the associated pulse length. Narrow bandwidths of 3.5MHz areused with long pulses on long range and wide bandwidths of 10-25MHz with shortpulses on short ranges. Any radar bandwidth of less than 5MHz will attenuate theSART signal slightly so it is preferable to use a medium bandwidth to ensureoptimum detection of the SART. The Radar operating manual should be consultedabout the particular radar parameters and bandwidth selection.Radar Side LobesAs the SART is approached side lobes from the antenna may show the SARTresponses as a series of arcs or concentric rings. These can be removed by theuse of the anti-clutter sea control although it may be operationally useful to observethe side lobes as these will confirm that the SART is near to the ship.Detuning the RadarTo increase the visibility of the SART in clutter conditions the radar may be detunedto reduce the clutter without reducing the SART response. Radar with automaticfrequency control may not permit manual detuning of the equipment. Care shouldbe taken in operating the radar detuned, as other wanted navigational and anti-collision information may be removed. The tuning should be returned to normaloperation as soon as possible.GainFor maximum range SART detection the normal maximum gain should be used.
11Anti-Clutter Sea ControlFor optimum range SART detection this control should be set to the minimum. Careshould be exercised as targets in sea clutter may be obscured. Some radar setshave automatic/manual anti-clutter sea control facilities in which case the operatorshould switch to manual.Anti-Clutter Rain ControlThis should not be used when trying to detect SARTs as the SART responses maybe removed by this control. Some sets have automatic/manual anti-clutter raincontrol facilities in which case the operator should switch to manual.Radar DisplaysThese sketches show the appearance of a SART response at different ranges.SART responsefrom distantliferaft (5-6 miles)SART responsefrom liferaft atmedium range (2-3miles).Note widening of“echos”SART responseclose to vessel(<1 mile).Display nowshows “rings”caused bystrength ofsignal
12Technical SpecificationFREQUENCY: 9.2GHz - 9.5GHzPOLARIZATION: HorizontalSWEEP RATE: 5µs per 200MHz nominalRESPONSESIGNAL: 12 sweepsFORM OF SWEEP: Forward: 7.5µs ± 1µsReverse: 0.4µs ± 0.1µsPULSE EMISSION: 100µs nominalEIRP: >400mW (+26dBm)RX SENSITIVITY: Better than –50dBm (0.1 mW/m2) (Note 1)DURATION: 96 hours in standby condition followed by a minimum 8hours of transmission while being continuouslyinterrogated with a pulse repetition frequency of 1kHz.TEMP RANGE: Operating: -200C to +550CStorage: -300C to +650CRECOVERY TIME: Following excitation: 10µs or lessANTENNA HEIGHT: Greater or equal to 1m (Note 2)RESPONSE DELAY: 0.5µs or lessANTENNA BEAM: Vertical: +/-12.5 degreesAzimuth: Omnidirectional to +/-2dBWEIGHT: SART only: 360gSART + pole: 510gSART complete: 530gDIMENSIONS: Overall, in bracket: 283 x 101 x 90mmBUOYANCY: BuoyantNote1. Effective receiver sensitivity includes antenna gain.2. The effective antenna height applies to equipment required to meetRegulation 6.2.2 of Chapter III and 7.1.3 and 8.3.1 of Chapter IV ofthe 1988 Amendments to the 1974 SOLAS Convention.StandardsComplies with IMO Resolution A.802(19)Test and Approval Standards are specified on the Declaration of Conformityfollowing.
13Declaration of Conformity
14Declaration of Conformity (page 2)
15Limited Product WarrantySubject to the provisions set out below McMurdo Limited warrants that this product will be freeof defects in materials and workmanship for a period of 12 months from the date of purchase.McMurdo Limited will not be liable to the buyer under the above warranty:-• for any defect arising from fair wear and tear, wilful damage, negligence, abnormalworking conditions, failure to follow McMurdo Limited's instructions (whether oral or inwriting) including a failure to install properly and/or to use batteries recommended and/orsupplied by McMurdo Limited, misuse or alterations or repair of the product by personsother than McMurdo Limited or an Approved Service Agent;• for parts, materials or equipment not manufactured by McMurdo Limited in respect ofwhich the buyer shall only be entitled to the benefit of any warranty or guarantee givenby the manufacturer to McMurdo Limited;• for the battery storage life which is specifically excluded from this warranty;• if the total price for the product has not been paid.McMurdo Limited does not make any other promises or warranties (express, implied orstatutory) about the product except where the product is sold to a consumer in which case thestatutory rights of a consumer are not to be affected.In order to be valid, claims must be made under the above warranty in writing as soon aspracticable after discovery of the defect or failure and within the warranty period referred toabove. Proof of purchase will be required. The claim should be sent together with the productin question to the address set out below or to an Approved Service Agent.Following a valid warranty claim McMurdo Limited shall be entitled to repair or replace theproduct (or part) in question free of charge, or at McMurdo Limited's sole discretion to refundto the buyer the price of the product (or a proportional part of the price). McMurdo Limitedshall not be liable to a buyer who is not a consumer for any other loss or damage (whetherindirect, special or consequential loss of profit or otherwise) costs, expenses or other claimsfor compensation which arise out of or in connection with this product. In the case of aconsumer McMurdo Limited shall only be liable where other loss or damage is foreseeable.Nothing shall limit McMurdo Limited's liability for death or personal injury caused by itsnegligence.This warranty is to be interpreted under English law.All enquiries relating to this warranty or Approved Service Agents should be sent to:McMurdo LimitedSilver Point, Airport Service Road, Portsmouth, Hampshire, PO3 5PB UKTelephone: Int + 44 (0) 23 9262 3900 Fax: Int + 44 (0) 23 9262 3998Web: www.mcmurdo.co.uk Email: service@mcmurdo.co.uk
16User Notes
17This page contains no other data
18McMurdo LtdSilver PointAirport Service RoadPortsmouthHampshireUnited KingdomPO3 5PBTelephone: Int +44 (0)23 9262 3900Fax: Int +44 (0)23 9262 3998sales@mcmurdo.co.ukwww.mcmurdo.co.ukA member of Chemring Group PLC86-920-001 Issue 1

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