Note 10—Drilling Fleet

Construction work in progress—For each of the three years in the period ended December 31, 2016, the changes in our construction work in progress, including capital expenditures and other capital additions, were as follows (in millions):


	Years ended December 31,
	2016		2015		2014
Construction work in progress, at beginning of period	$	3,735	$	2,447	$	2,708

Capital expenditures
Newbuild construction program		1,206		1,622		1,436
Other equipment and construction projects		138		379		729
Total capital expenditures		1,344		2,001		2,165
Changes in accrued capital additions		(86)		(11)		(45)
Impairment of construction work in progress		—		(52)		—

Property and equipment placed into service
Newbuild construction program		(2,557)		—		(1,522)
Other property and equipment		(265)		(650)		(859)
Construction work in progress, at end of period	$	2,171	$	3,735	$	2,447

Dispositions—During the year ended December 31, 2016, in connection with our efforts to dispose of non‑strategic assets, we completed the sale of the deepwater floaters Deepwater Navigator, M.G. Hulme, Jr. and Sedco 702 and the midwater floaters Falcon 100, GSF Grand Banks, GSF Rig 135, Sedco 704, Sedneth 701, Transocean Driller, Transocean John Shaw and Transocean Winner, along with related equipment. In the year ended December 31, 2016, we received aggregate net cash proceeds of $22 million and recognized an aggregate net gain of $13 million ($0.04 per diluted share, net of tax) associated with the disposal of these assets. In the year ended December 31, 2016, we received cash proceeds of $8 million and recognized an aggregate net loss of $9 million associated with the disposal of assets unrelated to rig sales.

During the year ended December 31, 2015, we completed the sale of the ultra‑deepwater floaters Deepwater Expedition and GSF Explorer, the deepwater floaters Discoverer Seven Seas, GSF Celtic Sea, Sedco 707, Sedco 710, Sovereign Explorer and Transocean Rather and the midwater floaters C. Kirk Rhein, Jr., GSF Aleutian Key, GSF Arctic I, GSF Arctic III, J.W. McLean, Sedco 601, Sedco 700, Transocean Amirante and Transocean Legend, along with related equipment. In the year ended December 31, 2015, we received aggregate net cash proceeds of $35 million and recognized an aggregate net gain of $14 million ($11 million or $0.02 per diluted share, net of tax) associated with the disposal of these assets. In the year ended December 31, 2015, we received cash proceeds of $16 million and recognized an aggregate net loss of $50 million associated with the disposal of assets unrelated to rig sales.

During the year ended December 31, 2014, we completed the sale of the deepwater floater Sedco 709, the midwater floater Sedco 703 and the high‑specification jackups GSF Magellan and GSF Monitor, along with related equipment. In the year ended December 31, 2014, we received aggregate net cash proceeds of $185 million and recognized an aggregate net loss of $1 million associated with the disposal of these assets. In the year ended December 31, 2014, we received cash proceeds of $30 million and recognized an aggregate net loss of $25 million associated with the disposal of assets unrelated to rig sales.

At December 31, 2016, the aggregate carrying amount of our assets held for sale was $6 million, including the midwater floater GSF Rig 140, along with related equipment, and certain corporate assets. At December 31, 2015, the aggregate carrying amount of our assets held for sale was $8 million, including the deepwater floater Deepwater Navigator and the midwater floaters Falcon 100, GSF Grand Banks, GSF Rig 135 and Sedneth 701, along with related equipment, and certain corporate assets.

See Note 6—Impairments.