Overhaul2 What Happens

Introduction

In my previous post, I defined what I mean by “overhaul.” Here I describe the basics of what goes on in overhaul and some things people might not realize that they don’t know about it. I won’t include the work that happens before shipyard leaders decide that the project team is “ready to start.” It includes budgeting, converting the Baseline Availability Work Package (BAWP) to the Authorized Work Package, ordering material, workforce training and allocation, general project planning, writing technical work documents, and test planning. I reserve the right to discuss them later because they are important.

Everything Happens for a Reason

Every overhaul consists of three major parts: setting the conditions to make it safe to do repairs, doing repairs and installing new equipment, and testing the work. These three parts can be divided more finely into: ship arrival and system shutdown; temporary system installation; system de-energization and draining fluid systems; work area isolation; rip out and component removal; repair and preparation for new equipment installation; component return and installation; testing; system restoration; and sea trials.

The phases occur roughly in this order, often overlap, and are sometimes repeated such as when a test fails and more repairs are needed. Like nearly everything about overhaul, the phases can be broken down even further. That isn’t necessary for my purposes.

Things You Didn’t Know About Overhaul

Many people think they understand overhaul, but some aspects are subtle or fiendishly counterintuitive. I will only mention the most important ones here: six months duration doesn’t mean six months of repair, schedule float is jealously guarded, the impact of critical trade skills, the start date isn’t always the start date, and adding more resources doesn’t always rescue a completion date.

People who haven’t experienced overhaul are frequently amazed by how short the repair period is. For a six month overhaul, it is about two months after setting the conditions for repairs and before the testing that comes after repairs. For a twelve-month overhaul, the schedule window for repairs is about four months. This is astonishing to outsiders, but nevertheless true.

Schedule float is a measure of how much delay a project can accept in its critical path work without delaying the completion date. Of the thousands of jobs in an overhaul, each with many sub-tasks, just one or two will have a duration long enough to finish close to the scheduled completion date of an overhaul. These jobs represent the critical path of the overhaul. Any delay to these jobs that consumes the time between job completion and the end date, the “float,” will be “critical” because it will delay completion by definition. It is sometimes possible to redesign the work after a delay to reduce the impact on follow-on work, but project team leaders try to avoid it because such changes consume valuable leadership attention and can impact the critical paths of work on other shipyard projects.

Shipyard project leaders constantly struggle to prevent outside organizations from adding work or requirements that could impact the overhaul end date. New work added two months before the scheduled end date would have to be done during the test program for even the shortest overhauls. It would almost undoubtedly delay the completion date. The 5-10% allowance for new work in overhauls (GAO, 2020) does not apply to something added during testing, regardless of the reason.

Project team leaders assiduously guard schedule float because it is always under assault. One example is organizations outside the shipyard that must complete work or supply necessary material or technical documentation before a key date (“key event”). Outsiders who are not responsible for delivering the ship on time will always ask, “When do you need it?” I was taught by a scheduler that the only way to respond to this question that doesn’t surrender float is, “You tell me when you can provide it and I’ll tell you the impact.”

It is not enough for a project to be supplied with engineering and production labor. Sometimes, the engineering or trade skill needed is specific for particular kinds of work and in very short supply. For example, most shipboard machinists, as distinguished from inside-shop machinists, are qualified to perform a variety of mechanical work on valves and other components. However, the skills and knowledge necessary to repair propulsion shaft seals and bearings, align main feed pumps, repair equipment in a submarine sail, or diagnose mechanical control systems are very limited. Many times, shipyards group the diverse skills for such work into teams that only work one job at a time.

Ship’s force and members of technical organizations outside the shipyard are frequently nonplussed, sometimes outright indignant, to learn that there is only one shaft seal repair team in a shipyard. They have seen thousands of workers all over the ship hammering away (sometimes literally) for months. Their reaction is like the Grinch when he learned that he failed to keep Christmas from coming. “How could it be so?” (Seuss, 1957).

Why not train more teams? The answer is: training is easy, maintaining proficiency for highly-skilled overhaul work is not. A six-month overhaul might require the expertise of the feed pump alignment team for just a few weeks, possibly not at all if no feed pump work was done. Submarine propulsion shaft seals, which have to be super quiet and free of excessive vibration, seldom need work. A shaft seal diagnosis and repair team might get to apply their skills once or twice a year because the seals are so reliable. That makes it hard to stay proficient.

In ship overhaul, the start date isn’t always the start date. An early start is necessary when a shipyard project team finds that it cannot accomplish the work required in the time allowed for the overhaul. The standard of proof for such a claim is very high, requiring the project team to use data from prior work of the same type and consider every possible way to redesign the work. The longest early start a project team can request without drawing unwanted external attention and beatings meetings is about four weeks depending on the impact that taking the ship off-line for maintenance has on operations. Is this cheating and subverting official schedule dates? Of course it is, which is probably why the practice sometimes gets subsumed into a more euphemistically titled “smart start.” It might be cheating, but it beats the rending of garments that results from an overhaul finishing late.

Technical and production labor resources are essential for overhaul, but they only speed up the work to a point. Certain work areas are very small (submarines) so adding more workers is impossible. Even when work spaces on ships are very large like aircraft carriers, it eventually becomes impossible to coordinate the efforts of more and more workers (Brooks, 1974).

Overhaul is Hard to Get Your Head Around

What you understand about anything depends on three things. First, what you notice from your personal experience (note-what you notice is heavily influenced by what you understand). Second, your position in the organization when you acquired your experience. Finally, the sense you make of your experience assisted by applicable theories and tools.

Overhaul can be hard to understand because it involves so much specialized knowledge and management practices characteristic to such large undertakings. You don’t plan hundreds of thousands of mandays of work on a weekend or around a water cooler. You need technical knowledge of ship systems and shipyard processes, resource procurement and management policies, and sometimes political sense (“You can’t say that!”). There are also factors beyond the control of participants like technical requirements, weather (hurricanes can’t be scheduled), material availability, and national priorities affecting ship schedules.

Many operators go through overhaul only once or twice in their careers so their perceptions about overhaul problems and what needs to be “fixed” can be strongly influenced by the job they had: enlisted Sailor, junior officer, department head, or CO/XO. A strategy or policy that seems imbecilic to a ship’s junior officer may be logical from the perspective of the CO. My favorite genre of U.S. Naval Institute Proceedings article is “What’s wrong with overhauls” written by junior officers who have recently completed their first one (McCarthy, 2022). Sometimes things in shipyards are imbecilic, but they can work better than “smarter” approaches.

Finally, unless you’ve received specialized training, you won’t understand the theories and tools of project management, work and resource management, and personnel management applicable to such large-scale undertakings. Practices that work well for the crew outside of the shipyard don’t scale in an industrial environment with thousands of workers and multiple complex projects in various stages of performance. Breaking a complex warship into little pieces, replacing or repairing some of them, and reassembling and testing everything create novel challenges even when parts aren’t left over.

“The test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function. One should, for example, be able to see that things are hopeless and yet be determined to make them otherwise” (Fitzgerald, 1936, p.41).

He could have been writing about overhauls.

My next post: what overhaul feels like to sailors. No wonder they get grumpy!

References

Brooks, F. P. (1974). The mythical man-month. Addison-Wesley. (many summaries online)

Fitzgerald, F.S. (1936). The crack-up: A desolately frank document from one for whom the salt of life has lost its savor. Esquire. (Esquire archive at classic.esquire.com)

GAO. (2020). Actions needed to address the main factors causing maintenance delays for aircraft carriers and submarines. GAO-20-588.

McCarthy, E. (2022). Take JOs out of the shipyards. USNI Proceedings, 148(10). Retrieved from https://www.usni.org/magazines/proceedings/2022/october/take-jos-out-shipyards

Seuss. (1957). How the grinch stole christmas! Penguin Random House.