Sir,

In compliance with the instructions contained in your minute of the 18th ultimo, I have now the honour to report, for the information of the Board of Trade, the result of my inquiry into the accident that occurred on the 10th ultimo, near Gray Rigg, on the London and North-western Railway.

The 12.47 a.m. mail train from Carlisle for London left Carlisle at 12.52, five minutes late, on the morning in question, consisting of an engine and tender, a guard's van, six composite and two third-class carriages, a Caledonian post-office (No.5), and a breakvan. The engine-driver ran for 42 miles, from Carlisle to Gray Rigg, at his usual speed, and passed Gray Rigg some three or four minutes hate, without stopping. He had received, a week previously, in a printed circular from the manager's office, instructions to slacken speed between the 25 � and 26th mile-posts from Lancaster, in consequence of the lifting of the road. He accordingly slackened his speed after passing the Gray Rigg station, from 36 to 25 miles an hour. It was a dark rainy morning, and the engine-driver perceived a little oscillation in his engine shortly after passing the 25 � mile-post. He thought that the road was "rather unusually rough," and, his steam having previously been shut off, he reversed his engine, and applied steam against the engine, with a view to stopping the train as quickly as possible. He did not whistle for the guard's breaks ; but the fireman, feeling also the rough condition of the road, and seeing that the engine-driver was reversing the engine, applied the tender break, which was previously partly on. The train was now descending a gradient of 1 in 106, and the engine-driver perceived shortly after-wards that something was "dragging" behind him. He brought his engine to a stand as soon as he could, and fearing that the down line, as well as the up line, might be obstructed, he sent his fireman towards Oxenholme ; and, after attending to his engine, he went northward to see what had happened.

The guard in the leading van perceived some unusual oscillation after leaving Gray Rigg, but did not think that anything was wrong until, after a few seconds, he felt a severe shock, which threw him down in the van. His break was already applied to a slight extent, and he got up as soon as he could, and turned it tight on, and kept it so until the train came to a stand.

The conductor rode in a second-class compartment of a composite carriage, which was the ninth vehicle behind the tender, and immediately in front of the post-office. He felt a "succession of violent oscillations or swayings," so much so that he jumped up in his compartment, for the purpose of attempting to seize the communication cord ; but before he could reach it he felt that his carriage was off the rails. He was much "thrown about," and after holding on by different parts of the carriage, and struggling as well as he could, he found his carriage come gradually to a stand across the line on which he had been travelling.

The guard in the hind van applied his break after passing Gray Rigg, according to his usual custom, and after passing a field gate near the 25 � mile-post, he felt a good deal of oscillation. He gave his break handle another turn or two, and while doing so he felt his van jump off the rails. He was stunned, and does not remember, either how his van came to a stand or how he got out of it ; but he ran back as soon as he recovered himself, with his lamp and detonating signals, to protect the train.

An examination of the line after the accident showed the train to be somewhat in the condition sketched in the accompanying diagram. The engine and tender and the heading van were all on the rails, and coupled together, and they had come to a stand at the Lamb Rigg level crossing, between the 25 � and 25 � mile-posts (from Lancaster), with the engine about 132 yards inside the former mile-post. Next behind the leading van was a carriage off the rails to the right (or east) by about nine inches. There were then three carriages on the rails, which did not appear to have left them, and two carriages off the rails, about 12 inches to the right, and the whole of these vehicles were still coupled together. The three carriages which had left the rails were somewhat damaged the first had the bands on the top of both the near springs fractured, and some of the spring-plates cracked; and the other two had damaged or broken ends, springs, and step boards. At 280 yards behind the front portion of the train, which thus remained coupled together, there lay two carriages, standing in a A form, across the up line, but still on their wheels. They remained coupled together by one side chain, the screw coupling having given way, and they were not much damaged except that the bands of the springs were fractured. Immediately behind the last-mentioned carriage, and coupled to it, was the post-office, on its side, entirely off the rails, and partially down the side of the embankment on which this part of the line runs. At 84 yards behind this post-office the hind van was lying partially on its side, and resting on its near wheels against the slope of a cutting on the near side of the line.

Strange to say, in spite of the serious nature of this accident, only two post-office clerks and one passenger, out of 40 or 50 who were travelling by the train, have complained of injury.

The most notable fracture connected with the rolling stock was that of the near leading wheel of the post-office. This was a wheel of the description known as Mansell's Patent, constructed with a cast-iron boss, wooden disc, and wrought-iron rings. for the attachment of the tyre. The disc of the wheel was found to be partly pushed off its boss for a distance of about three quarters of an inch towards the outside, while the boss remained firmly secured and keyed upon the axle. The outer cast-iron face-plate was cracked into three pieces, but the bolts which secured it to the inner plate forming part of the boss were all sound) and the nuts were tight upon them. The inner plate itself was broken into seven larger and one smaller pieces, and the fractures, though rusted in places, are still more or less bright where they have not been affected by water. The disc of the wheel appears, on examination, to have been previously used with the same boss, or with a different boss of the same description, inasmuch as it is doubly pierced, one set of holes, which have been much worn, having been plugged up; and another set of holes having been made for the boss which was on the wheel when the accident occurred. The disc had also been tightly packed with plates of iron to surround the boss, no doubt in consequence of its having become loose from previous wear. These and other points connected with the construction of the wheel and with its fracture are fully shown in the enclosed diagram, with which Mr. Bore, the carriage superintendent of the London and North-western Company, has been so good as to furnish me. The post-office to which this wheel belonged was the property of the Caledonian Railway Company.

The permanent way on this part of the line is laid with double-headed rails, weighing 84 lb. to the yard, and fished at the joints with wrought-iron suspended plates, and bolts and nuts. The chairs weigh 40 lbs. each, and are attached to the sleepers, each by two trenails and one wrought-iron spike. The keys are outside. The sleepers are laid transversely, three feet apart, on the average, from centre to centre. The road was relaid thus, with the ordinary London and North-western permanent way, about nine years ago. The roadway was in process of being lifted, an operation which had been continued for upwards of a fortnight; and the repairs which were being made at the same time had been carried on northward to within 100 yards of the first mark on the rail at the scene of the accident; while the lifting itself had been carried forward about a quarter of a mile north of that spot before the accident occurred.

The first mark observable on the permanent way after the accident, to show where any vehicle hind left the rails, was 217 yards south of the 25 � milepost. The outer rail. of the curve which there occurs, with a radius of about 70 chains, showed a wheel mark, as of a flange of a wheel mounting it and crossing it obliquely; and the outer jaw of the chair in front of the end of that wheel-mark was slightly chipped and indented, indicating where the wheel had fallen on the outside of the rail. There were, a little in advance, corresponding marks on the ballast and sleepers, showing where, after the mounting of an off wheel on the outer rail, a near wheel had also dropped inside the inner rail; and these marks continued on the sleepers, and could be traced to the spot where the post-office lay, 196 yards in advance, on its side, on the edge of the embankment.

At a distance of 56 yards from time first mark on the rail, it was observed that a vehicle had left the rail on the opposite or inside of the curve; and these marks conducted plainly and directly to the spot where the van lay resting against the side of the embankment. The road was not much disturbed, though the sleepers were damaged, between the point where the first mark on the rail was observable and the point where the hind van lay, nor indeed for 50 yards beyond that point; but for 30 or 40 yards further in advance the rails, chairs, and sleepers were carried completely over towards the edge of the embankment; and this was evidently done by the wheels of the post-office, before that vehicle turned over and fell on its side. The sleepers were much damaged, and a number of chairs were broken, for 300 yards further, and to the point where the engine and leading carriages came to a stand, but the rails were not displaced on that part of the line.

In considering the causes which have led to this accident, there would appear to be no doubt that the post-office was the first vehicle to leave the rails and that the principal damage to the permanent way was effected by the wheels of the post-office, about 150 yards in advance of the spot at which that vehicle had so left the rails. It appears plain also that the hind van was the second vehicle to leave the rails, and that it had nothing to do with the origin of the accident.

As regards the permanent way, the platelayers had lifted it for a quarter of a mile north of and past the site of the accident, and they had left the sleepers uncovered by ballast, and had no spare ballast about, or any more than was employed in packing up the sleepers during the lifting. As tried by the engineer of the line on the morning of Monday – the day following the accident – the superelevation of the outer rail on the curve was found to he 4 � or more inches, and to be uniform at and near the point where the first heel mark was discoverable ; and it was tested, with the same result, by the district engineer on the Sunday morning, five or six hours after the accident happened. The gauge between the rails is also said to have been correct to within a quarter of an inch. A number of new trenails now observable in the chairs are stated to have been inserted, some before, but more since, the accident; this remark applying specially to that part of the line where the post-office first left the rails; and two new sleepers have also been inserted since the accident, the one nine feet behind where tile first wheel-mark was visible, and the other opposite to that mark.

The wheel of the post office, though fractured as above described, was found to be nearly complete in all its parts ; but there were missing certain iron bolts or nuts, and a small portion of the inner plate (forming part of the boss), in a triangular form, with sides about two inches long. This portion was found twelve days after the accident, on the outside of the outer rail of a siding at Gray Rigg station, about two miles north of the scene of the accident, after having been much searched for by all the platelayers who were employed in maintaining and lifting the line. If this portion of iron dropped out of the wheel before the post-office left the rails, it would be fair to conclude that the wheel was fractured previously to the accident, and that the accident was caused by its failure ; but the evidence on this point is hardly conclusive, inasmuch as a number of broken chairs had been collected and taken from the site of the accident to the Gray Rigg siding two days before the finding of this piece of iron ; and it is not impossible that the piece of iron might have been carried, with other pieces of iron, to Gray Rigg after the accident. It might, or might not, have been previously discovered if it had lain at Gray Rigg from the time of the accident.

The carriage examiner at Carlisle, under whose scrutiny this train passed before it left for Gray Rigg, states that he carefully examined it all over, and that he is confident there was nothing the matter with any of the wheels when the train started from Carlisle.

The condition of the surfaces of fracture in the portions of cast-iron which have come from the broken wheel, is stated to have been nearly the same when the wheel was first examined after the accident as when I saw them on the 3rd May. Parts of these surfaces of fracture were still bright. Other parts were more or less covered with rust ; and it would appear that the rust was almost as extensive over the surfaces and as thick, five hours after time accident as on the 3rd May. There was no flaw in the material which would lead to weakness so as to cause those fractures, and it was impossible to say positively from their appearance whether there were any cracks in time wheel before the accident or not.

With a view to time further elucidation of this point I requested Mr. Worthington, the engineer, and Mr.Bore the carriage superintendent of the London and North-western Company, who took opposite views of the probable cause of this accident, to ascertain experimentally whether similar portions of metal, newly fractured and exposed under similar conditions to the action of water, would in five hours assume the appearances which were observed on the portion of the wheel in question five hours after the accident occurred. I enclose the letters which I have received reporting the results of these experiments ; and taking into consideration all the circumstances of the case, I am forced to the conclusion that the permanent way having been lifted, and time repairs having been in progress, the post-office was thrown off the rails in consequence of the defective condition of the permanent way, rather than from any failure prior to the accident in its own wheel.

I have, &c.

H.W. Tyler