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Signal Recording Apparatus Chart Productions of Graphic Signal and Engine Move- ment Recording Apparatus on Steamer George F. Brownell reproductions of a_ section of each chart from the graphic signal and engine movement recording apparatus on the steamer George F. Brownell, of the Erie Railroad Lake Line, as promised in the October issue, in which the first public reference to the apparatus was made. The charts show graphically the movement of the ship from the Erie dock at Washington street to the _ Santa Fe dock at Twenty-seventh and Robey streets, in the south branch of the Chicago river and were selected because of the constant maneuvering required in the swift current of the south branch. It will be noticed at once that the engines were being worked principally on backing signals and the time intervals are very short. The chart speed is 6 in. per hour, the ordinate spacing representing 714 min- ute intervals. Some of the signals are less than fifteen seconds apart, yet the engine response is clearly indi- cated not only as to direction but also as to speed. The latter is readily determined by the abscissae spacing, each space representing five revolu- tions. Not a response is missing. It will be at once apparent that, first, the signal actually given is recorded and, second, the action actually taken in the engine room is similarly re- corded, the graphs moving side by side at the same speed and operated by the same clock mechanism. oT HE REVIEW herewith presents Devices exist which indicate visually to the officer on the bridge what the engines are doing but so far nothing has been done to establish what was cone on the bridge or to mak¢ a synchronous graphic record of either the signals given or the action which followed. Hence frequent disputes as to "mistakes in signals'. The numerals in the margin have been added merely for convenience in comparison and do not appear on the charts. The time spacing is not shown, since, as previously intimated, the apparatus has been under observa- tion only, though continuously, and the speed and consequently time spac- ing, had not been finally determined when the charts were laid out. The overrunning of shift of signals is due tum of the pen itself, the pen at the to the momen- the shift being instantaneous, but does not affect the clarity of the record. Similarly the wavy appearance of the engine record is due to the extreme sensitiveness of the pen which is affected by any vi- bration of the ship. In the case shown the ship was light and the tremor usually observable under such conditions is quite apparent. The rec- ord, however, is not in any way af- 'fected thereby. Several interesting features will be discovered upon an examination of the charts. Beginning with 1, the first signal is. ahead slow: then "stop ,.. then mastern hall, "stop, "astern. slow: } "stop. "astern slow', "ahead slow', Ustop.,.. astern slow, stop, and if 5, "astern slow', followed almost at once by "astern half" then back to "astern slow", and within a few sec- onds to "ahead slow'. The action of the engines is perfectly clear both as to direction and speed. Similarly in 11 TELEGRAPH SIGNAL READ UP RECORD aes hee % is shown "astern slow" followed short- ly by "astern half', and®then "ahead slow" increased to "ahead half", swinging clear across to "astern half", the last working signal being "stop", followed by "finished with engines". The total time covered by this sec- tion is 93 minutes and records 51 sig- nals given and answered, an average of one every 1.8 minutes. The long- est interval between signals is 6 min- utes, the shortest about 10 seconds. The length of interval, however, or even the exact instant at which a signal is given, are relatively unim- portant compared with direction and speed, and since ahead and astern working and signals are shown on widely separated portions of the chart, agreement or disagreement is apparent instantly and on the most casual inspection. The apparatus is not considered to be a preventive of, but a means of fixing responsibility for, disaster, ENGINE SPEED RECORD. AND DIRECTION READ UP