Four members of Babcock's board of directors exercised share awards in the engineering support services firm over the past few days, building their stakes following a strong rise in the share price so far this year.Babcock has performed relatively well in 2013 despite the ongoing wider market volatility, with the shares up 21% since the start of the year. The impressive gains pushed the stock to an all-time high of 1,209p last month.The directors, namely Peter Rogers (Chief Executive), Bill Tame (Finance Director), Kevin Thomas (head of Support Services) and Archie Bethel (head of Marine & Technology), each exercised share awards and subsequently sold only enough to cover resultant tax liability and dealing costs whilst continuing to hold the balance, the company said.On August 9th, Rogers exercised 326,926 awards and sold 147,824 at 1,197p per share for just under £1.77m. The shares left over pushed his stake up to nearly 900,000 shares, equal to a 0.245% stake.Tame exercised 167,896 on the same day, selling 79,178 at the same price for £0.95m, with his holding rising to 0.124%.Then on August 14th, Thomas exercised 158,830 awards and sold 74,829 at 1,177.14p each for £0.88m; his stake rose to 0.046%. Bethel also exercised 132,109 on the same day, selling 62,216 at the same price for £0.73m.Top Director BuysFrenkel Topping Group (FEN) Director name: Mr Richard FraserAmount purchased: 48,327 @ 26.90p Value: £13,000Top Director SellsBabcock International Group (BAB) Director name: Mr Kevin ThomasAmount sold: 74,829 @ 1,177.14p Value: £880,842Babcock International Group (BAB) Director name: Mr Archie BethelAmount sold: 62,216 @ 1,177.14p Value: £732,369Lombard Risk Management (LRM) Director name: Mr Paul A E TusonAmount sold: 1,200,000 @ 11.75p Value: £141,000GETECH Group (GTC) Director name: Mr Peter StephensAmount sold: 30,000 @ 82.00p Value: £24,600Fidelity Japanese Values (FJV) Director name: Mr Simon FraserAmount sold: 24,000 @ 73.50p Value: £17,640BC