11.2 The Six Engineer License Classes, the Traction License & Qualifying Experience
Key Takeaways
- MCA 50-74-303 divides engineer licenses into six classes: first, second, third, agricultural, low-pressure, and limited low-pressure. The traction license is separate and is issued under MCA 50-74-306 and 50-74-307.
- Low-pressure covers steam not over 15 psig and water not over 50 psig and 250 °F; limited low-pressure covers hot water heating boilers to 30 psig and 210 °F and hot water supply boilers to 160 psig and 210 °F.
- Third class covers steam not over 150 psig saturated or 150 horsepower per hour and water not over 160 psig and 350 °F; second class covers steam to 250 psig, water to 375 psig and 450 °F, and steam-driven machinery not exceeding 100 horsepower per unit.
- MCA 50-74-304(7) lets applicants for low-pressure, agricultural, or third-class licenses substitute a department-approved training course plus 40 hours of supervised work verified by an engineer of equal or higher class; 50-74-304(8) provides a 6-hour course plus 8 hours route for limited low-pressure.
- MCA 50-74-305 allows reciprocity from states with equal or greater requirements, credit for United States military or merchant marine operating experience, and department-rule credit for approved training programs.
11.2 The Six Engineer License Classes, the Traction License & Qualifying Experience
Quick Summary: MCA 50-74-303 divides Montana engineer licenses into six classes — first, second, third, agricultural, low-pressure, and limited low-pressure — each bounded by explicit pressure and temperature numbers. A traction license is issued separately under MCA 50-74-306 and 50-74-307, and the statute is emphatic that the six classes do not entitle their holders to run a traction engine. MCA 50-74-304 sets the experience minimum for each class and provides training-course alternatives; MCA 50-74-305 adds reciprocity, military-service, and approved-training credits.
1. The Statutory Ladder — MCA 50-74-303
Section 50-74-303(1) states that engineers entrusted with the operation, care, and management of steam or water boilers and steam machinery "are divided into six classes." Subsection (2) then gives the schedule. These numbers are the exam. Memorize them literally.
| Class | Steam boilers | Water boilers | Other equipment |
|---|---|---|---|
| First class | All classes, pressures, and temperatures | All classes, pressures, and temperatures | All steam-driven machinery except traction and hoisting engines |
| Second class | Not in excess of 250 psig saturated steam pressure | Not in excess of 375 psig and 450 °F | Steam-driven machinery not to exceed 100 horsepower per unit, except traction and hoisting engines |
| Third class | Not in excess of 150 psig saturated steam pressure or not in excess of 150 horsepower per hour | Not in excess of 160 psig and 350 °F | — |
| Agricultural class | Not in excess of 150 psi saturated steam, and the boiler must not be operated more than 6 months of the year and not be operated for purposes other than harvesting or processing agricultural products | — | — |
| Low-pressure | Not in excess of 15 psig | Not in excess of 50 psig and 250 °F | — |
| Limited low-pressure | — | Hot water heating boilers not in excess of 30 psig and 210 °F; hot water supply boilers not in excess of 160 psig and 210 °F | — |
Reading the schedule correctly
The 100-horsepower figure in the second-class row is not a boiler size limit. It applies to steam-driven machinery — engines, turbines, and pumps driven by steam — and it is stated per unit. A second-class engineer's boiler ceiling is a pressure ceiling: 250 psig saturated steam, or 375 psig and 450 °F on the water side. Candidates who memorize "second class equals 100 boiler horsepower" will answer sizing questions wrong.
The third-class row uses "or," not "and." Steam boilers not in excess of 150 psig saturated steam pressure or not in excess of 150 horsepower per hour both fall inside third class. The 160 psig / 350 °F water limit is a separate clause covering hot water service.
Low-pressure and limited low-pressure are not the same thing. Low-pressure is the general commercial and institutional entry credential: 15 psig steam, or 50 psig and 250 °F water. Limited low-pressure is narrower and exists for hydronic building service: it authorizes only water, splitting hot water heating boilers (30 psig / 210 °F) from hot water supply boilers (160 psig / 210 °F). Both limited low-pressure categories cap at 210 °F, forty degrees below the low-pressure ceiling.
Agricultural class is a seasonal process credential, not a heritage-steam credential. Its defining conditions are the 6-month annual limit and the harvesting-or-processing purpose. It has nothing to do with steam traction engines.
2. The Traction License Is Separate — MCA 50-74-306 to 50-74-308
MCA 50-74-306(1) is unambiguous: "The licenses named in 50-74-303 do not entitle the holder to operate a traction engine." A first-class engineer with unlimited authority over stationary plant may not legally run a steam traction engine without a traction license. The statute also runs the other way: 50-74-306(5) provides that a traction license does not entitle its holder to operate any other class of steam machinery.
| Provision | Requirement |
|---|---|
| 50-74-306(2) | A person entrusted with the care and management of traction engines or boilers on wheels must pass a competency examination and procure a traction license |
| 50-74-306(3) | A person entrusted with the care, management, and operation of steam locomotives not addressed by federal regulations must likewise pass an examination and procure a traction license |
| 50-74-306(4) | The department may issue a license without examination to a holder of a valid out-of-state license if the 50-74-307(2) standard is met |
| 50-74-307(1) | Applicant must be 18 or older; must attend a department-approved steam school (school hours may be applied to the hour requirement); must have at least 50 hours total experience operating steam traction engines; and must pass a written examination prescribed by the department |
| 50-74-307(2) | Out-of-state licensees qualify if their state's standards are greater than or equal to Montana's |
| 50-74-308 | The department may waive the experience requirement for operators of traction engines maintained and operated as a hobby for restoration and show purposes of antique equipment |
| 50-74-104 | Dinkey engines — logging and mining railroad locomotives owned or operated by a company for its own business and not for general commercial purposes — are classed as traction engines, inspected as traction engines, and their operators and firemen must hold traction licenses |
Exam trap: The steam traction engine that shows up at a county threshing bee is a traction question, never an agricultural-class question. If it is on wheels, it is traction.
3. Qualification Requirements — MCA 50-74-304
Every applicant must be physically and mentally capable of performing the required duties, must be 18 years of age or older, must pass a written examination prescribed by the department, and must be found competent by the department for the class sought. The experience minimums are set by subsection, and the subsection numbering runs from the smallest class upward — the opposite of the way most candidates guess.
| Subsection | Class | Statutory minimum experience | DLI hour equivalent |
|---|---|---|---|
| 50-74-304(1) | Limited low-pressure | 2 months' full-time operating a boiler in this classification under a limited low-pressure or higher licensee | 320 hours |
| 50-74-304(2) | Low-pressure | 3 months' full-time under a low-pressure or higher licensee | 480 hours |
| 50-74-304(3) | Agricultural class | None — 18 or older, pass the written exam, be found competent | — |
| 50-74-304(4) | Third class | 6 months' full-time under a third-class or higher licensee | 960 hours |
| 50-74-304(5)(a) | Second class | 2 years' full-time on boilers and steam-driven machinery in this classification under a second- or first-class licensee | 3,840 hours |
| 50-74-304(5)(b) | Second class (upgrade) | Hold a valid third-class license plus 1 year's full-time experience under a second- or first-class licensee | 1,920 hours |
| 50-74-304(6)(a) | First class | 3 years' full-time under a first-class licensee | 5,760 hours |
| 50-74-304(6)(b) | First class (upgrade) | Hold a valid second-class license plus 1 year's full-time experience under a first-class licensee | 1,920 hours |
| 50-74-304(6)(c) | First class (upgrade) | Hold a valid third-class license plus 2 years' full-time experience under a first-class licensee | 3,840 hours |
The agricultural class has no experience requirement at all. That is unusual and it is tested. An applicant who is 18, passes the agricultural written examination, and is found competent by the department qualifies.
The training-course alternatives
MCA 50-74-304(7) — the alternative to subsections (2) through (4), meaning low-pressure, agricultural, and third class. An applicant 18 or older may be issued one of those three licenses if:
- (7)(a) the applicant completes a training course acceptable to the department that is specific to the class of boiler license sought, and passes the department's written examination specific to that class; and
- (7)(b) an engineer holding a license at least equal to the class sought informs the department that the applicant has worked with that type of boiler under the engineer's supervision for a minimum of 40 hours and is competent to operate a boiler of that class.
MCA 50-74-304(8) — the alternative to subsection (1), limited low-pressure: a 6-hour training course acceptable to the department, plus supervised experience. The DLI application checklist states the supervised component as 8 hours.
ARM 24.122.405(2)(a) sets the minimum length of approved courses: 30 hours, including classroom instruction and field or shop time, for all low-pressure and third-class boiler operating engineer training courses. ARM 24.122.405 also governs course approval — providers apply on department forms, submit a course outline with an hour breakdown, list books and source material, name each licensed instructor, and supply a sample completion certificate. Approved curriculum may not be modified without department approval, and approval stands until the department gives 30 days' notice of intent to withdraw it.
ARM 24.122.505(3) restates the documentary route: applicants for anything other than a first- or second-class license may furnish proof of a department-approved course plus verification from an engineer holding a license at least equal to the class sought that the applicant worked with that boiler type under supervision for a minimum of 40 hours and is competent. First and second class have no course substitute — those two classes require documented operating time.
4. Statutory Exceptions — MCA 50-74-305
Section 50-74-305 lists three allowable variances from the 50-74-304 minimums:
- Reciprocity. An applicant holding a valid license in the same classification from another state whose licensing requirements equal or exceed Montana's, who passes Montana's written examination and is found competent, must be granted a license in that classification. Note that reciprocity does not waive the Montana examination for the six engineer classes; only the traction license has an examination-waiver path, under 50-74-306(4).
- Military and merchant marine service. Operating experience in a classification accumulated in the United States military services or the merchant marine service, satisfactory to the department, may be accepted in lieu of the required operating experience for any license classification.
- Approved training credit. An applicant certified as having satisfactorily completed a prescribed training course from a department-approved institution or training program in the classification applied for may, pursuant to department rule, be credited with experience toward a first-, second-, or third-class or low-pressure license.
5. Documenting Experience — The Boiler Experience Verification Form
ARM 24.122.505(2) requires an application to include a completed application, the applicant's birth date and declaration of being 18 or older, the nonrefundable application fee, and documentation acceptable to the department establishing the requisite experience and qualifications. ARM 24.122.505(3)(b) requires the verifier to hold a license at least equal to the class the applicant is applying for.
The department's Boiler Experience Verification Form must be completed and signed by the licensed operator the applicant trained under and captures:
- Applicant name and dates of employment (start and end)
- Employer or business name and address
- For each boiler worked on: type (steam or hot water), safety valve setting in psi, dates operated from and to, and total hours operating the boiler
- The licensed operator's name, address, and phone number
- The licensed operator's license number and expiration date
- A signed affidavit declaring under penalty of perjury that the operator trained the applicant and that the applicant obtained the necessary experience, and acknowledging that a false statement or evasive answer may lead to revocation of licensure on ethical grounds
The safety-valve-setting column is the field that does the regulatory work: it is how the department confirms the experience was gained at or above the rated size of the class sought. The DLI checklist states the rule plainly — experience must be at rated size or above to qualify.
The DLI checklist also requires, in addition to the basic application: proof of training-course completion where applicable, official license verification from every state or jurisdiction in which the applicant holds or has ever held a professional license of any type, and documentation for any "yes" answer to a personal-history question. All license applications expire within one year of initial submission.
6. Class Selection Practice
| Equipment actually operated | Correct minimum class | Why |
|---|---|---|
| 12 psig steam heating boiler, 900 BHP | Low-pressure | 15 psig steam ceiling; the class carries no capacity limit |
| Hot water heating boiler, 28 psig, 205 °F | Limited low-pressure | Within 30 psig and 210 °F |
| Hot water supply boiler, 140 psig, 205 °F | Limited low-pressure | Supply boilers reach 160 psig at 210 °F |
| Hot water boiler, 45 psig, 240 °F | Low-pressure | Above the 210 °F limited ceiling, within 50 psig / 250 °F |
| Hot water boiler, 150 psig, 300 °F | Third class | Within 160 psig and 350 °F |
| Steam boiler, 125 psig saturated | Third class | Within 150 psig saturated steam |
| Steam boiler, 200 psig saturated | Second class | Above 150 psig, within 250 psig |
| Steam boiler, 300 psig saturated | First class | Above the 250 psig second-class ceiling |
| 140 psi saturated steam, 4 months/yr, potato processing | Agricultural class | Under 150 psi, under 6 months, processing agricultural products |
| Steam traction engine at a county fair | Traction license | 50-74-306(1): the 50-74-303 licenses do not cover traction engines |
| 250 hp steam turbine-driven feed pump | First class | Second class caps steam-driven machinery at 100 hp per unit |
A Montana hospital central plant runs a packaged Scotch marine steam boiler rated 80 boiler horsepower and actually operated at 125 psig saturated steam. Under MCA 50-74-303, what is the minimum class of engineer's license authorized to take charge of this boiler?
An applicant with no boiler operating time wants a Montana low-pressure engineer's license. Which combination satisfies MCA 50-74-304(7)?
A restored 1918 steam traction engine will be fired and driven at a Montana threshing bee. The operator already holds a valid Montana first-class engineer's license. What does Montana law require?