New Equipment, New Hazards – Lessons from the USS John S McCain Collision
On 21st August 2017, the USA Navy destroyer USS John S McCain collided with the oil tanker MV Alnic MC in the Straits of Singapore, killing 10 sailors onboard the McCain. Two
separate investigations undertaken by the US Navy [1] and the US National Transport and Safety Board (NTSB) [2] highlighted significant failures. One of these was the crew’s training
in the newly installed Integrated Bridge and Navigation System (IBNS), touchscreen workstations that control the steering and engines.
Although a naval warship at sea would appear to be a very different
environment from the anaesthetic room, this article will explore
why these lessons are relevant to anaesthetists by providing a brief
narrative of the incident, and highlight the key failures involving the
IBNS.
The incident
In the early hours of the morning of the incident, the McCain
entered the busy strait through which over 200 ships transit each
day. At the time of the incident, there were five other ships all
travelling in the same direction within a few miles of the McCain,
including the slower, larger Alnic MC just ahead and to the port
(left side hand side). Figure 1 is taken from the NTSB report [2] and
provides a visual summary of the following events.
As it was a period of very intense activity, the McCain’s captain
decided to divide the workload between two members of the crew
by transferring the engine controls from one IBNS workstation (the
Helm) to a second IBNS workstation (the Lee Helm). During the
transfer of the first engine control, the steering control was also
inadvertently transferred. The ship stopped responding to steering
commands and begun an unexpected turn to port which the crew
reported as ‘loss of steering’.
Shortly after, as the transfer of the second engine control was
completed, the captain ordered the ship to be slowed to
provide more time to manage the incident. Unbeknownst to
the crew, during the transfer of the engine controls, they had
been moved from a mode where both engines were controlled
together to one where they were controlled separately. Only
the port engine was slowed, and the resulting mis-matched
engine speeds exacerbated McCain's rate of turn into the path
of the Alnic MC.
Although the crew began to correct the turn within three
minutes of the initiation of the incident, it was too late and
the McCain was rammed on the side by the bulbous bow of
the Alnic MC (Figure 2 [2]). The collision crushed and rapidly
flooded one of the accommodation spaces, killing ten sailors
sleeping within. The crippled McCain managed to limp into
Singapore harbour, whilst the larger Alnic MC suffered only
superficial damage and no injuries to its crew.
Findings from the official reports
The US Navy and NTSB reports highlighted deficiencies
in leadership, situational awareness and seamanship that
contributed to the incident. However, both reports also
identified inadequate training in the IBNS.
The touchscreen IBNS replaced the traditional wheel and
throttles that control the ship. The McCain was one of the first
ships in the US Navy to have IBNS installed, but the crew never
had a formal training course. Instead, a senior crew member
was given a brief tutorial before being expected to train
more junior crew members, and despite further requests for
additional training this never materialised.
At the time of the incident, the captain had ordered the IBNS
to be placed in ‘Backup manual’ mode in a widespread belief
that it provided more direct control. However, this removed
an important safety measure. In the other modes, the transfer
of steering or engine controls required a four-step procedure
between the two workstations. However, in the Backup manual
mode, a single member of crew at the receiving station could
unilaterally take control with just one step. This was the error
that led to the steering being inadvertently transferred.
At this stage, the crew could have immediately taken control
back by an ‘Emergency-override-to-manual’ button at the top of
the IBNS workstation. However, they were under the mistaken
impression that this would have transferred the steering
controls to a different emergency workstation rather than their
workstation, and it was therefore not deployed.
Despite multiple screens across the McCain’s bridge
demonstrating the mismatch in engine speeds, this was not
noticed for over a minute. This discrepancy could have been
noticed earlier with the traditional mechanical throttle controls,
which can provide more tactile and visual feedback. Since the
publication of the two reports, the US Navy has decided to
pause the further introduction of IBNS and has returned back to
mechanical engine levers on the bridge of their destroyers [3]
Lessons for anaesthetists
Modern practice has been characterised by the introduction
of more complex anaesthetic machines and other ancillary
equipment. Although these machines have introduced safety
measures and reduced our workload, the McCain collision is
a good opportunity to reflect on our familiarity with our own
equipment. For example, the flowmeter interlock can prevent
the delivery of a hypoxic mixture of gas into the breathing
system element, but using low fresh gas flows can result in a
hypoxic mixture within the breathing system.
A further example of where correctly functioning equipment
fails to deliver the intended output is the position and warning
cues associated with the auxiliary common gas outlet switch.
Although highlighted a number of years ago by the Medicines
and Healthcare products Regulatory Authority [4], a recent Safe
Anaesthesia Liaison Group (SALG) report [5] indicated that this
is still an ongoing problem.
Are we adequately trained in the equipment we currently use?
When new equipment is introduced in the workplace, is there
a robust and comprehensive learning programme in place
with the appropriate instruction manuals readily available?
Specifically, are we aware how various design features
contribute to delivering safe anaesthesia, and which of these
features are lost if a specific mode is selected? Should a forum
be made available for individuals to discuss their experiences,
disseminate lessons learnt and correct mistaken beliefs?
Melvin Leong
ST7 Anaesthetic and Intensive Care Trainee
Institute of Naval Medicine
Oxford University Hospital NHS Foundation Trust
References
- Department of the Navy. Office of the Chief of Naval Operations.
Memorandum for distribution (November 1, 2017).
http:// s3.amazonaws.com/CHINFO/USS+Fitzgerald+and+USS+John+S+ McCain+Collision+Reports.pdf (accessed 14 October 2019).
- National Transportation Safety Board. PB2019-100970, 2019.
https://www.ntsb.gov/investigations/AccidentReports/Reports/ MAR1901.pdf (accessed 14 October 2019).
- 3. US Naval Institute News. Navy reverting DDGs back to physical
throttles, after fleet rejects touchscreen controls, 2019.
https:// news.usni.org/2019/08/09/navy-reverting-ddgs-back-to-physicalthrottles-after-fleet-rejects-touchscreen-controls (accessed 14
October 2019).
- 4. Gov.UK. Auxiliary common gas outlet (ACGO) for anaesthetic
machine – no fresh gas flow to patient with wrong setting
(MDA/2011/108), 2014.
https://www.gov.uk/drug-device-alerts/ medical-device-alert-auxiliary-common-gas-outlet-acgo-foranaesthetic-machine-no-fresh-gas-flow-to-patient-with-wrongsetting (accessed 14 October 2019).
- 5. Safe Anaesthesia Liaison Group. Patient Safety Update JanuaryMarch 2019, 2019. https://www.rcoa.ac.uk/sites/default/files/PSUSeptember-2019.pdf (accessed 14 October 2019).