1. IMO Type 1 / Type 2 / Type 3

이건 Chemical Tanker에서 매우 중요.

IBC Code 기반.

IBC stands for the International Bulk Chemical Code.

More specifically, the full name is: International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk.

LNG 선박에 IGC CODE가 적용되는 것처럼.

Many junior engineers initially misunderstand Type 1, 2 and 3 as simply “big” or “small” chemical tankers.

In reality, the classification is mainly based on:

“How dangerous the cargo becomes if released.”

Type 1

Highest hazard cargoes.

예:

• Highly toxic cargo
• Severe environmental hazard

Such as,,

• Sulphuric Acid
• Hydrofluoric Acid
• Certain chlorinated chemicals

특징:

• Highest segregation
• Double hull spacing 큼
• Cargo tank 위치 제한 많음

These vessels require:

• Maximum segregation
• Enhanced cargo tank protection
• Strict survivability standards

실제로 많지 않음.

Type 2

Medium-to-high hazard cargoes.

This is the most common category for modern deep-sea chemical tankers.

Typical cargoes:

• Methanol
• Xylene
• Benzene
• Caustic Soda
• Styrene Monomer

Many stainless steel chemical tankers operate mainly in this category.

Methanol, in particular, has become increasingly important due to the alternative fuel market and green shipping transition.

Type 3

Lower hazard cargoes.

Still regulated, but less dangerous than Type 1 or 2.

Examples:

• Vegetable Oils
• Palm Oil
• Lubricating Oil Additives
• Some non-toxic liquid chemicals

These vessels generally have simpler cargo arrangements and lower construction requirements.

위험성이 상대적으로 낮음.

Palm oil 등도 포함 가능.

검사관 입장 핵심:

Certificate of Fitness (다른선박에선 확인 잘 안하는데 케미컬선에선 중요)

에서:

이 배가 어떤 cargo까지 가능한가

확인해야 함.

2. Stainless Steel Tank vs Epoxy Coated Tank

이건 Chemical Tanker 가치 차이를 만드는 핵심.

This is one of the biggest commercial differences in the chemical tanker industry.

From the outside, two chemical tankers may look similar, but the cargo tank material dramatically changes:

• Vessel price
• Cargo flexibility
• Charter value

Stainless Steel Tank

High-end chemical carrier.

Cargo tanks are made from stainless steel, usually:

• SUS 316L
• Duplex stainless steel

Advantages:

• Excellent corrosion resistance
• High cargo flexibility
• Easier tank cleaning
• Higher charter attractiveness

Disadvantages:

• Extremely expensive construction cost

These vessels can carry:

• Methanol
• Acid cargoes
• High-purity chemicals
• Sensitive cargoes requiring contamination control

고급선.

장점:

• Corrosion resistance
• Cargo flexibility
• Cleaning 쉬움

단점:

• 매우 비쌈

대표 cargo:

• Methanol
• Acid cargo
• High purity chemical

검사 포인트:

Weld Area

중요.

특히:

• Crack
• Rust staining
• Pitting

확인.

Chloride Attack

스테인리스라도 chloride 문제 가능.

Epoxy Coated Tank

더 흔함.

장점:

• 비용 저렴

단점:

• Cargo 제한
• Coating damage 민감

Advantages:

• Lower construction cost
• Lower steel cost
• Simpler maintenance initially

Disadvantages:

• Limited cargo compatibility
• Coating damage risk
• Expensive recoating during drydock

These vessels usually carry:

• Palm oil
• CPP-related chemicals
• Less aggressive chemical cargoes

Real Price Difference (Approximate Market Example)

The price gap between epoxy-coated and stainless steel chemical tankers is massive.

For example:

Typical MR Chemical Tanker

Average size:

• 20,000 ~ 50,000 DWT
• Around 15,000 ~ 30,000 GT

Epoxy Coated Tanker

Approximate newbuilding price:

• USD 35 ~ 50 million

depending on:

• Yard
• Specification
• Eco design
• Scrubber
• Fuel type

Stainless Steel Chemical Tanker

Approximate newbuilding price:

• USD 55 ~ 90+ million

In some high-spec cases, the price can be nearly double that of coated tankers.

This is mainly due to:

• Stainless steel material cost
• Complex welding
• Tank fabrication difficulty
• Cargo system sophistication

STS 적용 선박 단가 2배까지 비쌈.

검사 시:

Zinc Silicate coating인가?

Pure epoxy인가?

에 따라 cargo 제한 달라질 수 있음.

3. Wall Wash Test

Chemical Tanker 핵심 개념.

특히:

• Methanol
• High purity cargo

에서 중요.

Tank cleaning 후:

탱크 표면 오염 남아있나?

확인.

보통 검사:

• Chloride
• Hydrocarbon residue
• Color
• Permanganate time

등.

실제 클레임 엄청 많음.

Cleaning 불량
↓

Cargo contamination
↓

수십만 달러 손실.

4. Nitrogen System

Deep knowledge 포인트.

많은 chemical cargo는:

• 산소 접촉 위험
• Polymerization 위험

있음.

예:

• Styrene Monomer

그래서:

Nitrogen Padding

사용.

즉:
탱크를 inert 상태 유지.

검사 포인트:

• N2 generator condition
• Oxygen analyzer calibration
• Pressure control

5. Polymerization Cargo

Chemical Tanker의 무서운 cargo.

대표:

• Styrene Monomer
• Vinyl Acetate

문제:

온도 상승
↓

자체 반응
↓

폭발적 polymerization 가능.

그래서:

Inhibitor 관리

매우 중요.

검사 질문 가능:

• Inhibitor monitoring?
• Temperature record?
• Emergency procedure?

6. Cargo Heating Complexity

Oil tanker보다 복잡.

왜냐면 cargo마다:

• Max temp
• Min temp
• Heating rate

다름.

과열 시:

• Cargo degradation
• Polymerization
• Color issue

발생 가능.

그래서:

Steam Heating Coil leakage

매우 민감.

특히:
Cargo contamination issue로 연결 가능.

7. Segregation Philosophy

Chemical Tanker 핵심 철학.

Oil Tanker보다 훨씬 엄격.

왜냐면:

Cargo A residue 0.01%만 섞여도
Cargo B 전체 unusable 가능.

그래서:

• Independent line
• Dedicated pump
• Separate vent
• Tank isolation

중요.

Surveyor는:

“Cross contamination risk”

항상 봐야 함.

8. Tank Atmosphere

Chemical Tanker는 atmosphere control 중요.

확인:

• O2
• VOC
• Toxic gas

특히:
Benzene cargo 등은 toxic exposure 위험 큼.

9. P/V Valve and Vent Mast

Deepwell system과 함께 중요.

Cargo vapor 처리 중요.

체크:

• Flame screen
• Free movement
• Corrosion
• Pressure setting

특히:
Sticky cargo residue 많음.

10. Vetting Inspector가 좋아하는 질문

실전 느낌.

질문 예시

“How do you prevent cargo contamination?”

좋은 답:

• line segregation
• dedicated pump
• tank cleaning verification
• wall wash test

“What is your procedure for tank entry after toxic cargo?”

확인:

• ventilation
• gas measurement
• enclosed space entry

“What actions are taken if coating damage is found?”

좋은 포인트:

• cargo restriction
• coating repair
• class consultation

11. 실제 Condition Survey에서 많이 보는 것

Cargo Tank Coating Breakdown

TOP deficiency.

Tank Dome Leakage

자주 나옴.

Butterworth Cover Gasket Damage

Cleaning system leakage.

Cargo Line Temporary Repair

클램프류.

주의.

PV Valve Corrosion

매우 흔함.

Surveyor’s Practical Perspective

In actual inspections, understanding whether the vessel is:

• Stainless steel
  or
• Epoxy coated

immediately changes the survey focus.

For epoxy-coated tanks, inspectors pay close attention to:

• Coating breakdown
• Rust spots
• Mechanical damage
• Previous repairs

Meanwhile, on stainless steel vessels, surveyors often focus more on:

• Weld integrity
• Pitting
• Chloride attack
• Cargo contamination history

because cargo quality expectations are usually much stricter on stainless steel chemical carriers.

Chemical Tanker survey는 결국:

1. Cargo Compatibility
2. Tank Coating
3. Segregation
4. Tank Cleaning
5. Toxic Safety
6. Nitrogen/Inert System
7. Cargo Heating
8. Contamination Risk

이 8개를 얼마나 이해하느냐 싸움