The Mangles was built in Bengal in 1803 and weighed 594 tons.  Convicts were transported to Australia on the Mangles in 1820, 1822, 1824, 1826, 1828, 1833, 1835, 1837 and 1840
On 9th June, the eve of his departure on the Mangles, *Lieutenant-Colonel Henry Thornton of the 40th Regiment was amongst the Officers and Gentlemen presented at the King's Court and Levee. Soon afterwards he embarked to join other members of the 40th regiment including Lieutenant Molinaux Dalrymple, Regimental Surgeon William Jones and 57 rank and file of the 40th.
The 40th had been serving in Ireland.
Following is an excerpt from Historical Records of the 40th (2nd Somersetshire) Regiment By Raymond Henry Raymond Smythies listing the ships that brought detachments of the 40th regiment to New South Wales in 1823 and 1824..........
Early in March 1823, the commanding officer, Lieutenant-Colonel Thornton received an intimation that it was intended to send the regiment to New South Wales. In the meantime it was ordered to proceed to Dublin, thence by sea to Liverpool, and after that by road to Chatham, in order to form guards for convict ships when required.
The head quarters reached Dublin on 15th March and occupied the Royal Barracks. On the 30th the whole regiment embarked at Pigeon House, in eight small vessels, and reached Liverpool the following day.
A twenty eight days' march, including three Sundays, brought the regiment to Chatham. The Regiment marched in three divisions; the first arrived at Chatham on 21st April; the second, consisting of two companies, halted, and remained at Deptford; and the 3rd reached Chatham on 23rd April.
During the next year the 40th was sent out, in small detachments, as guards on board convict ships to Australia. This was after several years' rough service in Ireland, and but a short period of rest in England........
Embarked 25th April 1823 on ship Albion. Lieutenant Lowe
Embarked 5th July 1823 on ship Asia Captain Bishop
Embarked 10th July 1823 on ship Isabella. Lieutenant Millar
Embarked 18th July 1823 on ship Sir Godfrey Wilestoe. Captain Hibbert
Embarked 29 July 1823 on ship Guildford. Captain Thornhill
Embarked 31st July 1823 on ship Medina. Lieutenant Ganning
Embarked 5 August 1823 on ship Castle Forbes. Lt.- Col. Balfour
Embarked 29 December 1823 on ship Prince Regent. Captain Stewart
Embarked 5th February 1824 on ship Chapman. Captain Jebb
Embarked 25 February 1824 on ship Countess of Harcourt. Captain Morow
Embarked 14 June 1824 on ship Mangles. Lt.- Col Thornton
Embarked 14 June 1824 on ship Princess Charlotte. Lieut Neilley
The Mangles departed Portsmouth on 13th July 1824 with 190 male prisoners.
Surgeon John Crocket
John Crockett kept a Medical Journal from 27 May 1824 to 1 November 1824. His first patient on the Mangles was George Burcher who was treated while the ship still lay at Portsmouth. The following prisoners and soldiers are mentioned in the surgeon's journal:
10th July - Portsmouth - Richard Smith - Rash
17 July - At sea - James Wallis (soldier) - pain in chest and abdomen
20 July - At sea - John Jeffkins - Pneumonia
20 July - At sea - Thomas Dobyns - soldier - generally unwell
25 July - at sea - James Anderson - soldier - headache and unwell
2 August - at sea - James Boon - urethritis
11 August - at sea - James Baker
23 August - at sea - John Greenfield - soldier - cough
6 October - at sea - John Toms - accident - fractured femur sent to Sydney hospital on arrival. 
On the 19th August 1824, five weeks after departure, Lieutenant Dalrymple submitted a long report to Colonel Thornton regarding a threatened mutiny by the convicts on the Mangles.......At 7pm on the 15th August a sentry had given the alarm that he had heard a noise as if the prisoners were rushing to the hatchway. The guard and crew were at once armed with muskets from a rack which had been built on the poop deck. Nothing came of the affair and Charles Bateson in The Convict Ships dismisses the attempted mutiny as one which perhaps existed only in the overwrought imagination of the sentry on duty that evening.
John Crocket remarked in his closing remarks:
Many slight ailings and accidents did occur all of which were by timely interference arrested. I am happy to have it in my power to state that the whole of the prisoners entrusted to my charge are in a better state of health than when they were delivered to me. My general system of cleanliness and regulation which was most tenaciously enforced saved me infinite trouble in my medical duties as well which exercise both of mind and body could not fail to have the most desired effect. Through the whole of the passage nearly a fifth have been constantly employed at School and to which I most strictly attended myself daily. This has been a source of great pleasure and amusement to me particularly as it has been crowned with success. - signed John Crocket 
The Mangles with 199 prisoners arrived at Sydney on 27th October 1824, a voyage of 106 days . There had been no deaths of convicts on the voyage out, however it was reported that two men (crew?) had been lost overboard.
The prisoners were disembarked on 1st November 1824
Departure from the Colony
In November the Australian reported that the Mangles was about to commence loading for the return voyage to England. She was said to be larger than any ship that ever sailed from Port Jackson laden with colonial produce. Her burthen was not less than 600 tons. 
The Mangles, full of a cargo of wool and timber, sailed for London on 10th February 1825. Passengers included Judge Advocate John Wylde ; Charles McArthur, Dr. Crocket R. N., Lieut. Carr, Dr. Quid R. N., (?Charles Queade), Mr. Broadfoot, Mr Uther and Mrs Harvey. In sailing from Sydney the Mangles touched on the Sow and Pigs, but received no damage. After clearing the heads the winds suddenly abated, and she driftedvery near the rocks under the Light house where she was forced to anchor. She was rescued from her dangerous situation by boats from two nearby Merchant vessels. 
3). Lieutenant Molineux Dalrymple joined the army on 24 December 1818 and was appointed Ensign 25 March 1819. He was appointed Captain in April 1827.
4). *Henry Thornton was a Lieutenant in the Scots Greys in 1796, became Captain in the 40th foot on 25 November of the same year, and Major on 2nd August 1802. On 4th June 1811, he received the brevet rank of lieutenant-colonel, and nine days later became Lieutenant-colonel in the regiment. He commanded the 1st battalion during some of its most arduous service in the Peninsula, and received the gold cross for Talavera, Nivlle, Orthez and Toulouse, in addition to the silver medal with seven clasps and a Companionship of the Bath, to which he was appointed on 4th January 1815. Being called as a witness at a general court martial in London on the return of the 40th from America early in 1815, he was not present at the battle of Waterloo, but rejoined the regiment shortly afterwards in France, and commanded it from that time until 1827 when he exchanged with Colonel Valiant into the 82nd Regiment. He retired the following year, and died at Camberwell aged 77 in April 1856 (Records of the 40th Regiment (2nd Somersetshire)
5). John Crockett was also employed as surgeon on the convict ship Prince of Orange in 1822 (to VDL)
8). Return of Convicts of the Mangles assigned between 1st January 1832 and 31st March 1832 (Sydney Gazette 14 June 1832; 28 June 1832).....
John Gouder (?Goodyer)- Bricklayer assigned to Mary Raine at Parramatta
Thomas Munroe - Errand boy assigned to William Sherwin at Parramatta.
9). NSW Courts Magistrates, Newcastle Police Court: 1823-1825, 1826-1827 (Ancestry) 6 November 1826...... Henry Cooper per ship Mangles, assigned to the surveying department charged with insubordinate and riotous conduct in striking a fellow prisoner and provoking him to a fight and disrespectful language to Mr. Lowe....... . sentenced to 50 lashes for striking a fellow prisoner and provoking him to fight and 25 lashes for disrespectful language and insubordinate conduct towards Mr. Lowe