Abstract: There is provided an apparatus for tracking a pig travelling inside a tubular object. The apparatus includes a sensor arrangement including at least one position sensor configured to detect a passage of the pig travelling inside the tubular object and a tracking device. The tracking device is configured to: process the detected passage of the pig from a run of the pig through the tubular object to determine a travel time of the pig; using the determined travel time, calculate a speed of the pig through the tubular object; and using the calculated pig's speed, perform real-time tracking of the pig's position inside the tubular object in a subsequent run of the pig through the tubular object.

Abstract: A scraper pig for cleaning tubes and pipelines comprising a flexible core provided with a casing in which scraper studs are embedded in a manner whereby they protrude sufficiently to perform a cleaning action when they are propelled through the tube. A method for the manufacture of the pig and the design of the stud is also provided.

Abstract: An intelligent pig for pipeline monitoring comprises a single body containing signal transmitters and receivers provided with replaceable rings for centering the body within the pipeline, the rings may be provided with brushes which help center the pig within the pipeline and also aid its passage through pipelines which may contain bends and/or be of variable diameter, the pig may be used in combination with a cleaning pig to provide combined activities using a common driving force.

Abstract: An intelligent pig for pipeline monitoring comprises a singles body containing signal transmitters and receivers provided with replaceable rings for centering the body within the pipeline, the rings may be provided with brushes which help centre the pig within the pipeline and also aid its passage through pipelines which may contain bends and/or be of variable diameter, the pig may be used in combination with a cleaning pig to provide combined activities using a common driving force.

Abstract: A method of monitoring a tube or pipeline, wherein an IP comprising an electronics module arrangement, is driven along the interior of the tube or pipeline by fluid pressure, wherein the IP transmits monitoring signals through the fluid that provides the pressure to the wall of the tube or pipeline, receives signals returned from the wall, analyzes the returned signals and stores data relating to the condition of the wall of the pipeline.

Abstract: A scraper pig for cleaning tubes and pipelines comprising a flexible core provided with a casing in which scraper studs are embedded in a manner whereby they protrude sufficiently to perform a cleaning action when they are propelled through the tube. A method for the manufacture of the pig and the design of the stud is also provided.

Abstract: A method of monitoring a tube or pipeline, wherein an IP comprising an electronics module arrangement, is driven along the interior of the tube or pipeline by fluid pressure, wherein the IP transmits monitoring signals through the fluid that provides the pressure to the wall of the tube or pipeline, receives signals returned from the wall, analyses the returned signals and stores data relating to the condition of the wall of the pipeline.

Abstract: A pipeline pig for inspecting the internal condition of a pipeline, especially for determining the wall thickness therealong, comprises three discrete modules containing electronics distributed therebetween. The modules are individually protected by polyurethane outer coverings and are interconnected by electrical cables. A flexible arrangement results for use in narrow and tortuous pipelines. The pig carries its own power supply so that results from its ultrasonic scanning system can be processed and stored on board for subsequent downloading.

Abstract: A marine escape system has a passage extending between an evacuation point on a vessel and an inflatable life raft. The passage is arranged vertically and is connected to a succession of hoops. The connection between at least one of the hoops and the life raft is achieved by flexible elongate members of differing flexibility These are held in tension so that, as the life rafts move on swell, the passage extends and retracts from the lower end first. This allows the passage to have only one exit which can be within a life raft so that persons can evacuate from the ship without ever being exposed to the elements. The passage may include a helical tube or a tube with angled panels.

Abstract: A releasable connector for connecting a shackle bolt on a liferaft to the depending end of a davit cable is set in a safe condition for boarding and lowering of the liferaft. In the safe condition, a hook member supports the shackle bolt and is itself locked in its supporting position by a latch member. A coupling spring connected between the hook member and the latch member operates to one side of its dead-center position to urge the latch member into the locking position. A first downward pull on a lanyard causes a pawl member to engage a tooth on the latch member to move the latch member from its locking position to a drive position in which the coupling spring operates to the other side of its dead-center position and urges the latch member into its drive position.

Abstract: In a phase comparison radio navigation system in which a prime and one or more secondary transmitting stations radiate phase-locked signals of the same frequency in a time-shared sequence, phase locking at the secondary station or stations is effected by using a common phase comparator both for locking a phase memory oscillator to the received prime signals and for locking the secondary signals at the antenna with the phase memory oscillator.

Abstract: In a phase comparison radio navigation system in which phase-locked signals are radiated from spaced stations to be compared in phase in a receiver, the receiver has a separate phase memory oscillator for each received signal, the phase memory oscillators operating at the same frequencies (apart from differences due to Doppler shifts) and being locked to their respective signals from the transmitting stations and display units are provided each with selector means enabling any display unit to effect phase comparison between any pair of outputs from the memory oscillators.

Abstract: In a phase comparison radio navigation system in which spaced transmitters radiate phase-locked signals in a time-shared sequence, in order to enable a receiver to be operated on any selected one of a large number of different frequencies, a phase memory in the receiver for giving a continuous output representative of the phase of an intermittently received signal, comprises a controlled oscillator giving an output of a frequency much higher than the received frequency, a frequency divider providing a first sub-multiple of the oscillator frequency, a frequency synthesizer providing a heterodyne signal at a second sub-multiple and a phase comparator providing an output controlling the oscillator in accordance with the phase relation between the divider output and the output of a mixer mixing the received signal with a heterodyne signal.

Abstract: In a phase comparison radio navigation system using transmissions from spaced stations in a time-sequence, for synchronising the timing of the transmissions, and for synchronising switching in a receiver, the timing control means include digital counting means counting down from the output of an oscillator phase locked to one of the received signals, and a timing identification signal is transmitted from one station for initially synchronising the counter timing.