His brother, also a military engineer serving Charles, was taken prisoner by the parliament forces in 1644, but after some time on bread and water, was released in a poor state of health.

Martin Beckman in 1660 petitioned Charles II for the place of royal engineer, formerly enjoyed by his brother, and mentioned that he "was ruined and severely injured by an accident at an explosion in the preparation of fireworks to be shown on the water in the king's honour."

He was accordingly employed as an engineer, and his skill in laboratory work led to his appointment on 6 June 1661 to the expedition under Edward Montagu, 1st Earl of Sandwich as "firemaster with and in his majesty's fleete".

[1] In 1663, the new governor of Tangier, the Earl of Teviot, pressed Beckman to design such fortifications as he considered necessary, estimated to cost £200,000, but dismissed him within days with a promissory note on two Dutch merchants in lieu of pay.

[citation needed] Beckman was so infuriated at his treatment by Teviot that he went to Spain and offered to betray Tangier to the Duke of Medina-Sidonia in exchange for a "Regiment of Foot" and money.

He stated, in a petition to the king and council for a trial, that he had been half a year a close prisoner through the malice of one person for discovering the designs of the Spaniards and others against his majesty.

[1] In 1672 he visited Carlisle and Clifford's Fort at the mouth of the Tyne, plans of which and some cleverly executed water-colour views are in the British Museum.

[2] In the following year he was an engineer of the ordnance train in the expedition against Holland under Prince Rupert, and took part in the naval engagements of 28 May, 4 June, and 11 August.

On 3 March a royal warrant secured to him the reversion of chief engineer of Great Britain on the death of Sir Bernard De Gomme.

During the absence this year on account of ill-health of Sir Henry Sheeres, Surveyor-General of the Ordnance, Beckman acted for him.

In 1689 he was busy with the defences of Hull and Berwick-on-Tweed, and obtained a royal warrant (23 August) for the execution of his proposed fortifications in the Isle of Wight.

[1] At the end of May 1694 he sailed in command of the train and of all the bomb-vessels and machines, with the troops under Thomas Tollemache, and arrived with the fleet at Camaret Bay on 7 June, when the land attack failed.

[1] On 22 May 1695 Beckman was appointed to the command of the ordnance train and the machine and bomb-vessels for the summer expedition to the straits of Gibraltar, and took part in the operations on the coast of Catalonia, returning home in the autumn.

He exercised a similar command in the summer expedition under Lord Berkeley, which sailed at the end of June 1696 to "insult the coast of France".

These enterprises created such alarm that over a hundred batteries were ordered by the French ministry to be erected between Brest and Goulet, and over sixty thousand men were continually in arms for coast defence.

[1] Early in 1697 Beckman surveyed all the bomb-vessels, ten of which he reported to be in good condition and fitted to take in twenty mortars "which are all we have serviceable".