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Massachusetts Third Class Engineer License EXAM QUESTIONS
AND CORRECT VERIFIED SOLUTIONS LATEST UPDATE THIS
YEAR – JUST RELEASED
Massachusetts Third Class Engineer License Exam – Study Guide
10-Line Exam Coverage in Points Form
1. Licensing Authority & Regulatory Framework – Department of Fire Services (DFS),
Engineering Division; M.G.L. Chapter 146; 522 CMR (Board of Boiler Rules); 5-year
renewal cycle with 30 hours of continuing education required; license fee: $100 initial,
$90 renewal
2. Third Class License Scope & Restrictions – Engineer-in-Charge of boilers not exceeding
150 HP (solid fuel) OR 500 HP (liquid/gaseous fuel, electric, atomic); engines/turbines
not exceeding 50 HP each; responsibility for daily operation, maintenance, and
supervision of operators; no second plant without licensed engineer in attendance
3. Eligibility & Examination Prerequisites – 1.5 years experience in boiler/steam power
plant as engineer, fireman, control room operator, water tender, auxiliary operator, or
engineer's assistant; OR 1 year First Class Fireman license; OR 1 year equivalent license
(Merchant Marine or another state); US citizenship or declaration of intent;
endorsement by licensed engineer/fireman (same or higher grade)
4. Written & Oral Examination – Open-book? Closed-book? (typically closed-book for
stationary engineers); multiple-choice and essay; covers boiler operation, steam
principles, ASME codes, Massachusetts laws (M.G.L. Chapter 146); examinations held
monthly; application entitles applicant to one exam; may reapply after 60 days
5. Boiler Fundamentals & Operation – Firetube vs. watertube boilers; horsepower
calculation (BTU/hr OUT ÷ 33,475); heating surface calculation (π × diameter × length ×
number of tubes); forced-draft vs. induced-draft fans; high-pressure boilers > 15 psig
steam; internal inspection required annually (522 CMR)
6. Combustion & Fuels – Fuel oil grades; stoker systems (mechanical coal feeding for solid
fuel under 150 HP); heat transfer efficiency; Dulong's formula; NOCASH elements; excess
air and incomplete combustion; flame safeguard systems (photocell/UV detection)
7. Feedwater Systems & Water Treatment – Deaerators (remove dissolved oxygen and
non-condensable gases); reverse osmosis (removes dissolved salts, >99% ion rejection);
ion exchange softeners; scale formation from calcium/magnesium salts; chlorides as TDS
indicator; feedwater line secured after burner shutdown
8. Steam Traps, Turbines & Condensate – Inverted-bucket steam traps (buoyancy change);
thermostatic traps; float traps; steam turbine operation sequence; over-speed trips at
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20% above rated speed; reaction turbines (pressure drop across stationary and moving
blades); carbon ring seals; surface condenser vacuum maintenance
9. Pumping Systems & Hydraulics – Centrifugal pumps (flow varies with pressure and
speed); rotary pumps; reciprocating pumps; feedwater pumps; condensate return;
cavitation; pressure measurement (Bourdon tube gauge reads differential pressure –
submerged gauge reads 0)
10. Safety, Inspections & Recordkeeping – Annual internal and external inspections by
Authorized Insurance Inspector or State District Engineering Inspector; Engineer-in-
Charge responsibilities (ensure licenses posted, logbooks completed, certificates valid,
notifications submitted); notice of change in Engineer-in-Charge within 7 days
100 MCQ Questions with Rationales
1. Under Massachusetts General Laws Chapter 146, a Third Class Engineer may be in charge of
a boiler not exceeding 500 horsepower based upon the relieving capacity of the safety valves
when steam is generated by which fuel source?
A) Solid fuel only
B) Liquid or gaseous fuel
C) Electric or atomic energy
D) Both B and C
Correct Answer: D
Rationale: Massachusetts General Laws Chapter 146, Section 49 specifies that a Third Class
Engineer may have charge of a boiler not exceeding, in the aggregate, 150 horsepower when
solid fuel is burned, or 500 horsepower when steam is generated by the use of liquid or gaseous
fuel, electric or atomic energy, or any other source of heat .
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2. What is the minimum experience requirement to be eligible for the Third Class Engineer
examination in Massachusetts?
A) 6 months in a boiler plant
B) 1 year in a boiler plant
C) 1.5 years in a boiler or steam power plant
D) 2 years in a boiler or steam power plant
Correct Answer: C
Rationale: M.G.L. Chapter 146, Section 50 requires that an applicant for a Third Class Engineer
license must have been employed in a boiler or steam power plant as a steam engineer,
fireman, control room operator, water tender, auxiliary operator, or engineer's assistant for not
less than one and one-half years .
3. How long is a Massachusetts Third Class Engineer license valid before renewal is required?
A) 1 year
B) 2 years
C) 3 years
D) 5 years
Correct Answer: D
Rationale: Massachusetts engineer licenses are valid for five years. License holders of all grades
must complete 30 hours of continuing education during the term of the license to renew .
4. What is the fee for a Third Class Engineer license in Massachusetts?
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A) $50
B) $75
C) $100
D) $150
Correct Answer: C
Rationale: The Massachusetts Department of Fire Services lists the fee for a Third Class Engineer
license as $100. The renewal fee is $90 .
5. What is the engine horsepower limitation for a Third Class Engineer license in
Massachusetts?
A) 25 horsepower each
B) 50 horsepower each
C) 75 horsepower each
D) 100 horsepower each
Correct Answer: B
Rationale: A Third Class Engineer may be in charge of engines and turbines not exceeding 50
horsepower each .
6. Which of the following is NOT a valid pathway to eligibility for the Third Class Engineer
examination?
A) 1.5 years experience in a boiler or steam power plant
B) 1 year holding and using a First Class Fireman's license
Massachusetts Third Class Engineer License EXAM QUESTIONS
AND CORRECT VERIFIED SOLUTIONS LATEST UPDATE THIS
YEAR – JUST RELEASED
Massachusetts Third Class Engineer License Exam – Study Guide
10-Line Exam Coverage in Points Form
1. Licensing Authority & Regulatory Framework – Department of Fire Services (DFS),
Engineering Division; M.G.L. Chapter 146; 522 CMR (Board of Boiler Rules); 5-year
renewal cycle with 30 hours of continuing education required; license fee: $100 initial,
$90 renewal
2. Third Class License Scope & Restrictions – Engineer-in-Charge of boilers not exceeding
150 HP (solid fuel) OR 500 HP (liquid/gaseous fuel, electric, atomic); engines/turbines
not exceeding 50 HP each; responsibility for daily operation, maintenance, and
supervision of operators; no second plant without licensed engineer in attendance
3. Eligibility & Examination Prerequisites – 1.5 years experience in boiler/steam power
plant as engineer, fireman, control room operator, water tender, auxiliary operator, or
engineer's assistant; OR 1 year First Class Fireman license; OR 1 year equivalent license
(Merchant Marine or another state); US citizenship or declaration of intent;
endorsement by licensed engineer/fireman (same or higher grade)
4. Written & Oral Examination – Open-book? Closed-book? (typically closed-book for
stationary engineers); multiple-choice and essay; covers boiler operation, steam
principles, ASME codes, Massachusetts laws (M.G.L. Chapter 146); examinations held
monthly; application entitles applicant to one exam; may reapply after 60 days
5. Boiler Fundamentals & Operation – Firetube vs. watertube boilers; horsepower
calculation (BTU/hr OUT ÷ 33,475); heating surface calculation (π × diameter × length ×
number of tubes); forced-draft vs. induced-draft fans; high-pressure boilers > 15 psig
steam; internal inspection required annually (522 CMR)
6. Combustion & Fuels – Fuel oil grades; stoker systems (mechanical coal feeding for solid
fuel under 150 HP); heat transfer efficiency; Dulong's formula; NOCASH elements; excess
air and incomplete combustion; flame safeguard systems (photocell/UV detection)
7. Feedwater Systems & Water Treatment – Deaerators (remove dissolved oxygen and
non-condensable gases); reverse osmosis (removes dissolved salts, >99% ion rejection);
ion exchange softeners; scale formation from calcium/magnesium salts; chlorides as TDS
indicator; feedwater line secured after burner shutdown
8. Steam Traps, Turbines & Condensate – Inverted-bucket steam traps (buoyancy change);
thermostatic traps; float traps; steam turbine operation sequence; over-speed trips at
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20% above rated speed; reaction turbines (pressure drop across stationary and moving
blades); carbon ring seals; surface condenser vacuum maintenance
9. Pumping Systems & Hydraulics – Centrifugal pumps (flow varies with pressure and
speed); rotary pumps; reciprocating pumps; feedwater pumps; condensate return;
cavitation; pressure measurement (Bourdon tube gauge reads differential pressure –
submerged gauge reads 0)
10. Safety, Inspections & Recordkeeping – Annual internal and external inspections by
Authorized Insurance Inspector or State District Engineering Inspector; Engineer-in-
Charge responsibilities (ensure licenses posted, logbooks completed, certificates valid,
notifications submitted); notice of change in Engineer-in-Charge within 7 days
100 MCQ Questions with Rationales
1. Under Massachusetts General Laws Chapter 146, a Third Class Engineer may be in charge of
a boiler not exceeding 500 horsepower based upon the relieving capacity of the safety valves
when steam is generated by which fuel source?
A) Solid fuel only
B) Liquid or gaseous fuel
C) Electric or atomic energy
D) Both B and C
Correct Answer: D
Rationale: Massachusetts General Laws Chapter 146, Section 49 specifies that a Third Class
Engineer may have charge of a boiler not exceeding, in the aggregate, 150 horsepower when
solid fuel is burned, or 500 horsepower when steam is generated by the use of liquid or gaseous
fuel, electric or atomic energy, or any other source of heat .
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2. What is the minimum experience requirement to be eligible for the Third Class Engineer
examination in Massachusetts?
A) 6 months in a boiler plant
B) 1 year in a boiler plant
C) 1.5 years in a boiler or steam power plant
D) 2 years in a boiler or steam power plant
Correct Answer: C
Rationale: M.G.L. Chapter 146, Section 50 requires that an applicant for a Third Class Engineer
license must have been employed in a boiler or steam power plant as a steam engineer,
fireman, control room operator, water tender, auxiliary operator, or engineer's assistant for not
less than one and one-half years .
3. How long is a Massachusetts Third Class Engineer license valid before renewal is required?
A) 1 year
B) 2 years
C) 3 years
D) 5 years
Correct Answer: D
Rationale: Massachusetts engineer licenses are valid for five years. License holders of all grades
must complete 30 hours of continuing education during the term of the license to renew .
4. What is the fee for a Third Class Engineer license in Massachusetts?
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A) $50
B) $75
C) $100
D) $150
Correct Answer: C
Rationale: The Massachusetts Department of Fire Services lists the fee for a Third Class Engineer
license as $100. The renewal fee is $90 .
5. What is the engine horsepower limitation for a Third Class Engineer license in
Massachusetts?
A) 25 horsepower each
B) 50 horsepower each
C) 75 horsepower each
D) 100 horsepower each
Correct Answer: B
Rationale: A Third Class Engineer may be in charge of engines and turbines not exceeding 50
horsepower each .
6. Which of the following is NOT a valid pathway to eligibility for the Third Class Engineer
examination?
A) 1.5 years experience in a boiler or steam power plant
B) 1 year holding and using a First Class Fireman's license
